refrain from using sms lingo dude.. uncool. :\
welding is not something you wanna do for case fabrication. rivets are what comes to mind.
btw, just few points..
1. you will be making precision parts.. CAD software is needed for that. google Sketchup is an approx advanced drawing app atmost.. dont expect precise measurements from it.
2. you need milling/press machines to cut and fold metal sheets. jagged edges will mean sloppy work and lots of cuts and scratches..
3. you must have an elaborate knowledge of joint formation and their contribution to making a structure rigid.
4. speaking of precision, this is how professional cabinet maker do it:
they design the cabinet in a CAD s/w, and then generate a code for the computerised milling machine from that design. the code contains the coordinates and commands of where to make make cuts, holes, etc. then the code is sent to the machine and the machine creats an open box from a sheet of metal. then the cut sheet is fed into a press, which makes folds at the right places to make a box[press is computerised too
].
