Overview of the tools you probably will use
Jigsaw:
This is probably the most used tool ever in cockpit building. Unless you want to build it entirely by using your arm-power 
Tablesaw:
A tablesaw can be most handy if you plan to make your own panels. This makes sure your cuts are straight and your angles are nice 90°
Dremel:
A dremel can be used for all sorts of things. If you plan to build FSbus and you do not want to make the PCB's yourself but you think you can mange the soldering works .. you might buy the PCB's undrilled and then drill them yourself with a dremel. Will save you quite a few $'s or 's
Drills:
Try to avoid using the wrong type of drills for the wrong materials. You won't get good results and you might end up braking the things. A good idea is to find a vertical column to fit your power-drill inside. Helps for maximum precision!
Paint vs spray paint:
When painting or spray painting make sure that you use primer where needed. Experianced painters will think this is a stupid remarc though I didn't use it and my expensive spray paint got soaked up completely by the wood panel ! Other reason for using primer is that on metal parts the paint might not stick.
Soldering iron:
Knowing how to solder is a very important step for cockpit builders. Find a good soldering iron and keep a little sponge in the area which you wet each time you plan to solder. Keep the hot tip clean !! Also a fine tip helps. Heat up the 2 parts a bit (carefull when heating electronic parts ! The heat might damage them. Then apply the tin to it and you'll see it will flow on the 2 parts at once. (when not heating the parts the tin might flow and stick to your iron instead of the parts !)
Related to soldering is PCB(=Printed Circuit Board) making. Check PCB Making page. (-- Manuel)
CNC:
If you happen to be so lucky to have or to have access to a CNC machine you can skip some of the previously mentioned tools. With a CNC you can cut, engrave and router your parts and panels. No need to say that this enables you to go trough with backlighting your panels!
Some people build their own CNCs or retrofit old mills/lathes with CNC capability
There are plenty of people on the web working on DIY CNC machines. More about CNC here: CNC, mills, routers, and CNC PCB drills
A less obvious tool, but none the less if you make your panels yourself this might be interesting.