I can't even begin to imagine why you'd think this was a dumb question.
This isn't _quite_ what I'd think of as "cabinet making", although I guess you are making cabinets.
Industrial carpentry is OK. But look for a course that teaches furniture making (portable boxes made in workshop) rather than house building (making fixed buildings by working on-site). You can learn by many methods, but a workshop course will give you hands-on experience with big expensive machines that you won't get otherwise.
Guitar amps etc ?
By the sound of things, you're going to be making fairly simple plywood boxes, covered in a separate covering. Now this is a fine thing to be doing (you're selling electronics here, not boxes) and it's also pretty simple woodworking.
Somewhere out there are a couple of books (can't remember the names, but they're around) called "How to build cabinets for stage gear" and "How to build loudspeaker enclosures". You need to read these, because fancy-ass cabinetry by James Krenov won't last 5 minutes with roadies humping it. And speaker design is somewhere between rocket science and voodoo chicken sacrificing.
Google this newsgroup for book list recommendations. I know many of us have suggested lists out on the web. I'd suggest
"Tage Frid Teaches Woodworking, Vols 1 & 2" <(Amazon.com product link shortened)>
"The Accurate Table Saw", Ian Kirby <(Amazon.com product link shortened)> This is going to be your main working tool - learn how to drive it.
You can probably skip Flexner's book on finishing, unless you're planning some. "Understanding Wood Finishing" <(Amazon.com product link shortened)>
You might find a few of the kitchen cabinet books, like Jim Tolpin's <(Amazon.com product link shortened)> to be useful.
That's probably how most of us did it. Some stuff needs information to be given to you though, as it's expensive (or even painful) to work it out for yourself.
I'm assuming you're making guitar amps (if not, tell us). These are boxes of 1/2" plywood, butted and reinforced in the corners. then they're covered with assorted fabrics and leathercloths and have edge reinforcements screwed on. They also have obscure cutouts for metal sub-panels.
Your material is good quality 1/2" plywood. Chipboard (particle board) is garbage, MDF is heavy and doesn't have the mechanical stiffness (can be useful for speakers and valve amps though). Birch ply is the best. Rainforest ply is often of poor quality, unless you choose carefully, and tropical ply is unsustainable.
You won't believe how much you spend on timber! Check your suppliers out carefully - there's a big difference.
Workbench (doesn't need to be big, must be solid) Assembly bench (can be low and flimsy, but needs to be separate from the workbench - stacked pallets at a pinch) Workmate (optional - for holding the big things the workbench can't)
Pencils (hard, soft, average, 0.7mm mechanical) Get a good journal / big bound notebook too (NOT a ringbinder) and write down or draw _everything_ so it doesn't get lost afterwards. Make regular notes on how big you made things, or on recipe proportions, so you can reproduce them later. 12" steel rule, good tape measure (Stanley Leverlock with the base lock lever) Carpenter's 10" square, Big (3' - 4' leg) framing square Big steel compasses with screw adjust (also small ones, dividers etc.) Small block plane (Lee Valley low angle) Rolls of sandpaper in 60,80,120,180,240 grit and a few hand blocks Knife (rough utility) Knife (razor sharp and kept for marking out) Saws; cheap "Borg" tenon saw, panel saw, 12" hacksaw, coping saw Clamps; malleable iron G clamps (to fit over edge of workbench + 2") and lots of cheap long aluminium sash clamps. Hand-held countersink bit, screwdrivers, sharp awl, files (lots more too)
PVA-based glue. Avoid polyurethanes. Contact glue too for coverings, and epoxy is always handy (get a West System trial pack and some microballoon filler)
Table saw Hand-held circular saw Jigsaw Hand drill Biscuit jointer Router Bench drill
Don't get hung up on these. Woodworking is about skill, not shininess of the tools.
The table saw slices up your plywood. You can spend a little or a lot - largely depending on how much space you have, how much budget, and how fast you want to work. The Ryobi 3000 is "entry level" here, a "classic" Unisaw is great for hardwood furniture making, but for an industrial shop working plywood you want (not need) something like this <http://www.axminster.co.uk/product.asp?pf_id#279&recno=3 This has a sliding table, it's big enough to eat a whole 8'x4' sheet, and it has a scoring saw (second tiny blade up front, that gives a cleaner cut on the underside). Whatever you have, have suitable blades to hand, including a fine plywood blade.
You _need_ a good tablesaw. You _need_ accurate square cuts in the sizes you're working at. Bigger and more expensive is better, but there are ways to work with just that cheap Ryobi.
Hand-held circular saw. So your table saw is small and it won't take a whole sheet - then use this first. Place the sheet on a few wooden trestles, then rip it down in size with this, just to make it manageable. You'll want a cheap saw (£50 not £100) from a good maker, because it's lighter weight and you're only cutting plywood. Fit a proper plywood blade to it first. A long straight edge guide helps too.
Jigsaw. Get a really good one, such as the Bosch GST2000. This vibrates less, so you get a usably good cut with less clean-up. It's not a desperately useful tool (go circular if you can), but it will work inside a hole that the others can't.
Biscuit jointer. The quick way to make simple joints in plywood. Fairly cheap too.
Router. Not that much use (for these simple boxes, you should get most done with the saw). Very cheap though and a cheap 1/4" router with a bearing-guided chamfer bit is often useful. Later on, tool up with a real 1/2" router and maybe a table - you might start making repeat patterns with a template. No substitute for a biscuit jointer.
Bench drill - mainly for metalworking, so get one that offers slower speeds too. You're going to be doing some panel making, and this is much nicer with a bench drill than a hand-held.