My final product changed a little since but I included my Sketchup model for those who would like it. Sketchup was useful but I must say it is not my favorite CAD software (then again, its hard to beat free).
Disclaimer : This instructable uses power tools. They are not to be taken lightly and should only be used by those who know what they are doing and are careful with them. I am in no way responsible for your mishaps. That also goes for the usage of this table. It is meant for light loads and will probably break if you try to do something stupid with and/or around it (no diving boards for you). I believe this to be safe and sound for the intended purpose but I accept no responsibility for your actions/workmanship.
Step 1: What You Will Need.
-Ear and eye protection
-Chop saw (almost essential but you could manage with a miter box).
-Circular/Table saw (optional, i had my local hardware store cut my plywood for me).
-Pocket hole jig (you could make do without it but it does look allot nicer this way).
-Clamps of some sort.
-Vacuum cleaner (especially if you live in an apartment like me)
-Screws. I used 8 x 1-1/4 particle board screws (they have a flat holding surface for the pocket holes).
-8' x 4' - 3/4" pine plywood*
-6 1"x3" x 8' pine
-1 1"x6" x 8' pine
-3 1"x2" x 8' pine
*3/4" plywood is excessively strong for this purpose and you can probably substitute for cheaper 1/2". I got 3/4" since i'm planning on making a work bench with the leftovers.
**you could probably have less waste with 10' or 12' wood but 8' is the longest I can fit in my car without keeping the hatch up.
Step 2: Cut Your Plywood.
If you are lucky enough to own one of these dandy tools, cut it yourself but be careful (an acquaintance of mine recently maimed his hand with a table saw).
Step 3: Cut Your Legs (the Table's Legs Silly).
Ok so this may be a little confusing since I tried to optimize wood usage a little.
1- Take four of the 1"x3" and mark them at 39".
2- Measure to make sure its 39" (i know i can be annoying but this really does save you some wobbly screw ups).
3- Line up you blade so your cutting on the other side of the 39" you just measured whilst barely touching the line (so that all your cuts are the same).
4- Cut (one at a time).
5- Measure, mark and remeasure the next 39".
6- Line up and cut.
7- Save the end for later.
8- Repeat for the next piece.
Step 4: Cut Your Side Bars.
Using the leftovers from step 3, and following the same directions, cut four 12-3/4" long pieces.
Along the same lines, take your 1x6 and cut two 12-3/4 pieces.
Step 5: Drill Pocket Holes and Assemble Your Sides.s.
The rest will vary a little bit according to the pocket hole jig you are using but use your head and read your pocket hole jig's instructions and you should be fine. One important thing, if you don't have much experience (i sure didn't) with your pocket hole jig, use two junk 1x3 pieces to practice. Doing this taught me two things. Firstly, my jig goes too deep if I set it to it's 3/4" board setting. I had to use the 1/2" board setting so that my screws had enough material left on the other side. Secondly, with this thin board, I found that to avoid cracking, pre-drilling was a must on the second board (the one without the pocket hole).
For the top board (1x6) the hole placement is a little arbitrary. I put them were I thought they would interfere the least with the plywood. When you have drilled out all your pocket holes, use screws in the pocket holes to mark out were they line up on the cross bars and pre-drill them so they don't crack.
When you've got your pre-drilling done, its time to get screwing. You wont want to tighten them all the way just yet, otherwise you'll have trouble lining up the bars on the other side. Instead, put the screws down with about 1/8" left to go. Once all your screws are in, then go around tightening them all up.
Repeat these steps to make the other side (identical).
Step 6: Cut Your Front/back Pieces.
Also cut two 26-1/2" pieces from the rest of the 1x6.
Step 7: Drill More Pockets and Assemble Your Front/back.
Drill said pocket holes, pre-drill opposing boards and screw your front/back pieces together.
Step 8: Assemble Your Frame.
Mark your front and back pieces at 6, 16, 26 and 36 inches (from the top) to give you an idea of were to put you pocket hole jig. Drill the pockets and, as always, pre-drill the side pieces so they don't crack when you screw them together. When your screwing everything together, it helps to have a helper hold the pieces in place (I use a clamp).
Step 9: Cut and Install Your Shelve Supports.
Cut up you 1x2s into six 2' and six 1' pieces (length accuracy isn't a problem for these so even if it ends up 23", don't panic).
The following instructions work the same for all levels just switch around the measures.
For each side (front, right, back and left), lightly clamp the corresponding 1x2 so that it's bottom almost lines up with the bottom of the cross bar. Measuring from the ground, tap one end of the 1x2 until it it's top is at exactly ( 35-1/4" or 25 or 15). This may seem funny but lining up each peace as perfectly as possible will avoid wobbly shelves.
Once you have it lined up, tighten the clamps, pre-drill (being careful not to make it all the way through) and screw it in. You shouldnt go too crazy on the screws (I used two for the 1' pieces and four for the 2' pieces).