Someone PM'd me asking what supplies would they need to start building. If he doesn't know, then there must be many more who doesn't. So I'll try to list everything you'll need to complete an enclosure. Please feel free to add anything I missed that have helped you with your build.
1. 3/4" MDF wood - ~$20 a sheet
2. Wood Glue. Titebond seems to be the choice for many
3. Nails. 1 5/8" does fine for me.
4 BAR CLAMPS - at least 3, you can choose the size according to the size of enclosures you build. I recommend 30" or more.
5. Caulk - to fill up any holes that may lead to leaks from those not-so-straight cuts.
6. Silicone - GE window/door clear silicone was recommend by PV audio and I would have to take his word for it. Also used to prevent air-leaks. I just bought 2 tubes of them today.
7. Corner clamps - may come in hand to get those nice 90 degree angles just right.
8. Straight edge rule - I used a yard stick.
9. Caulking Gun.
10. Paint - for the port. Black is a famous color.
1. Table Saw - for the cuts.
or Circular Saw
2. Drill - cordless or not. Phillips bit for the screws, and drill bit for predrilling (make sure the bit is not as big or bigger than the screws)
3. Jigsaw or Router - for subwoofer cutout (thx Eldorado)
4. Sander - Will work wonders for those off cuts.
Also dont' forget protective gear. googles, dust mask. Breathing in all that mdf dust does not feel good. Hopefully i've covered everything.