Tools, you can never have enough tools in your shed, if ever you feel that you don't have room for more, that means that you need a bigger shed! If you buy a tool, and use it once, it was money well spent, if you use it twice, it was a bargain!
I can often be found sifting through tool catalogues, when not studying repair manuals, or actually doing repairs. I will create lists of tools and equipment that are required for any forthcoming jobs, make wish-lists of items that "will come in handy, someday" and am often prompted to plan jobs when I come across pieces of equipment that grab my attention. Also, by maintaining an aquaintance with the various catalogues, if I come across a problem, I will be familiar with the tools required for the job, and have a fair idea of the anticipated cost, location and or delivery lead time to aquire the tools I need.
Tidy tool storage is essential.
Always clean and return your tools after use, that way you'll be able to find them the next time you need them, and they will be clean. It is a horrible feeling to pick up a grotty screwdriver or spanner.
I started with a 5 drawer cantilever type tool box, and a few basic hand tools. As the collection became bigger, and the box heavier, I gained more tool boxes, until I could no longer find anything without having to rake through all the boxes. Then one year, I received a handsome Christmas bonus from work, and invested it in some rather nifty stacked tool chests. The lower chest is fitted with castors which have a brake mechanism, thus the tools can be brought to the job, if required. Though I prefer to have a dedicated place for the chest.
With a basic set of spanners and screwdrivers, a socket set, some feelers and a wire brush, simple servicing can be done, as you delve deeper into your machine, you will find more tools are required, various sizes of hammer, chisel, punch, drift etc. A set of picks, similar to those used by dentists, is very handy for removing seals and O-rings, and for installing them. Mirrors for examining those hard to reach areas and torches to light the way.
The more tools the better, usually cheapo tools will get the job done just as well as expensive ones, however when the going gets tough, the cheap ones tend to crap-out. That said, better to have something than nothing.
Screw driver sets are cheap enough from markets and hardware shoppes, Having a good range will ensure that you have a good fit on that screw head, so that you don’t damage it. If you take a medium sized flat (or slotted) screw driver and round off the corners, this then becomes your paint tin opener, I have seen several people badly injured from using a regular screw driver for this task.
Socket sets, if possible try to get hex (6 point) as opposed to bi-hex (12 point), as hex provide the better fit, although the benefit of a 12 point is that it offers better access where space is tight. Hex key sockets, socket adaptors, extensions, sliding T-bars, ratchets, knuckle bars. All so very useful.
You need a torque wrench, a cheap deflection type will help, but really you need a positive indication that your torques are accurate and even, so get a “click” type one upto 100 or 150 lbs/ft. It is important that these are backed off to zero when not in use, otherwise the internal spring will become weakened, and so the reading will be inaccurate.
A variety of spanners (wrenches) in all formats, metric and imperial sizes, ring, open, combination, box, socket, hex key, torx key etc. and multiples too, as you will invariably need to “back-up” one end of a nut/bolt as you remove them.
Vice or mole grips, again various sizes, pipe wrenches and “speed” wrenches which will grip the most rounded of nuts very well.
Punches, pin, taper, hole and centre. All have their place.
Rubber mallet, with these you can “welly” soft castings without damage, (also great for putting in tent pegs).
Pliers, again these come in all shapes and sizes, and each type will make itself useful. Surgical forceps are like having an extra hand, they can be locked in place if you need to let go of something without it falling back down that awkward hole, very good when soldering wires too as they will position an individual wire whilst insitue on the machine.
Special tools.
Occasionally, I need to make "one off" tools for specific tasks. One tool I recently made was for locating the rear brake return spring on the Triumph. Made from 1/16" galvanized steel wire rope, and with a SWL of 250kg, this material is more than adequate for the job in hand. By making a loop, or eye, at either end, using "yankee" splices, the business end being about 1" dia. and the other being 6" dia and with a section of plastic fuel hose as padding. I placed the small eye over the hook of the spring, and by bracing against the frame of the bike, I managed to locate the spring first go, without nipping any fingers, or being reduced to curses.
SPECIAL EQUIPMENT
As funds and space allow, it is worth investing in as much special equipment as possible. Whilst a washing up bowl and a gallon of parafin are good for cleaning parts, a dedicated parts bath, with pump and strainer makes such a difference. Filled with Gunk, it can be left to wash parts whilst others are made ready. Note: Gunk is best for this task, some degreasing agents I have used (in particular "Tetraclean") have done more damage than good as they can attack aluminium alloys, or even lift paint.
Whilst expensive, a motorcycle lift will make an awkward job a breeze. By raising the bike off the ground, a better working height is achieved. I have one that lifts under the frame rails to a height of about 18". This type will allow both wheels to be removed simultaneously. Other types of lift will raise the machine higher, but may not allow for wheel removal. When purchasing any equipment is worth considering the pros and cons.
Metalworking lathes, again these can be expensive, but if you are likely to need to make things on a regular basis, they can be money well spent. Small model engineers lathes should have ample capacity for turning bushes, spacers and drifts. Larger lathes for making spindles, skimming drums and discs and truing crankshafts.
Drill press and machine vice, when you have to drill a hole, workholding is most important. If the workpeice can be secured, secure it, if it can't, figure a way of doing so, I have a very nasty scar from taking a short cut once, well several actually!
On the subject of drilling, it is important to keep your bits keen, a sharpening device will pay for itself with a few uses. Use cutting fluid or compound, select the most suitable drill speed available, and be aware that when the bit "bursts through" it is very likely to snag, causing the drill to react.
When using a bench grinder, wear goggles, don't wear gloves, always let the stone do the work, i.e. apply light pressure with the workpiece, allow the wheel to maintain it's correct speed (as this is the the key to abrasion) and cool the workpiece in water regularly. Keep the stone well dressed, and maintain minimum clearance between the wheel and the work rest.
Rules for angle grinders are similar, let the disc do the work, use quality consumables, use cutting discs for cutting and grinding discs for grinding.
Measuring equipment, a vernier caliper with depth gauge is a good starting point here, internal and external micrometers, dial test indicators (dti) for truing up and measuring end float.
Taps and dies, if you are making your own parts, or dressing damaged threads, these are available from engineers suppliers, auto factors, flea markets and car boot sales etc.
Zeus charts, a pocket sized, oil resistant set of data and charts, giving valuable information on tapping drill sizes, thread form dimensions, tolerances of fit, hole spacing etc. Again, available from engineers suppliers. Also, for the serious shedologist, a copy of the Machineries Handbook, the engineers bible, is a must. A printed copy is very expensive, but I picked up a well formatted cd-rom version on ebay for a few pounds recently.
Tools, you can never have enough tools in your shed, if ever you feel that you don't have room for more, that means that you need a bigger shed! If you buy a tool, and use it once, it was money well spent, if you use it twice, it was a bargain! 
Occasionally, I need to make "one off" tools for specific tasks. One tool I recently made was for locating the rear brake return spring on the Triumph. Made from 1/16" galvanized steel wire rope, and with a SWL of 250kg, this material is more than adequate for the job in hand. By making a loop, or eye, at either end, using "yankee" splices, the business end being about 1" dia. and the other being 6" dia and with a section of plastic fuel hose as padding. I placed the small eye over the hook of the spring, and by bracing against the frame of the bike, I managed to locate the spring first go, without nipping any fingers, or being reduced to curses.
SHEDOLOGY: GRASS ROOTS ENGINEERING.