MAKING THE CUTS 

You need to start your poker table build with your plywood. I started with 2 sheets, but later discovered I wanted a 3rd sheet of plywood for the Baseboard.  I used high quality plywood (3/4" thick and 8' x 4'). The plywood (from Home Depot @ $29/sheet) is called Arauco and apparently comes from Chile. Oak or Pine would work just fine too, just get whatever you think looks the best for your finished poker table. It should already be sanded. If you're trying to save money, you can buy 1 high-quality piece (used for the exposed racetrack), and 2 cheaper pieces (used for the rail and baseboard). It might save you a few bucks. I'd stay away from MDF though.  Do you absolutely have to use 3 sheets?  No, but I did. If you can think of an acceptable way to mount everything together, then go for it. 2 sheets would work but you will not be able to mount the racetrack and rail to the baseboard, unless you figure something else out. I did not want to mount the racetrack by screwing partially through it (under the exposed part). Think it through and build it however you like.
You will need an axis for drawing your arc. If your table is 8' x 4' you should measure 24" from all 3 sides of the end of the plywood. The axis will be where the lines meet (exactly 24" from each side and the end). To do this I simply measured 24" acrosse the end, and put a pencil mark (exactly 1/2 the width of the sheet). Then measure 24" up each side and put a mark. Stretch a long ruler (able to stretch the entire width of the table), and align the ruler with the 2 marks on each side. Draw a very faint line across.
Now measure 24" across that faint line, and put a mark. Next draw your line up from the mark at the end of the table (where you made your first mark). The intersection of the lines is your point. Next, gently drive a small tack nail into the intersection point. I didn't want to use string because it stretches, so I used picture-frame wire. It worked okay, but your best bet would be a jig, compass or a ruler. Just stick the nail through the hole, and trace the arc while keeping your pencil on the proper measurement. This works well, but I later discovered that using a ruler would be better/easier (see later photos).
If you look closely you can see the arc I've drawn. I used picture-frame wire because it doesn't stretch like string. However, I still found it difficult (with my unsteady hands) to trace it. You can used whatever you want (string, wire, large compass, jig, ruler). I would suggest using the ruler method (described in a later picture). Click here to find out how to make a Jig.
Use your Jigsaw to cut the first piece of wood along the arcs. For the 2nd piece, tracing your acrs is even easier. Simply lay the (already cut) 1st piece on top of the (uncut) 2nd piece. Trace the arcs with your pencil. It doesn't have to be perfect because both outer edges will be covered with foam & vinyl for the rail. Just try to get it as close as you can.
Hint, mark an asterick on one end of the sheet on both the outer circle and the inner circle. This will help you align it later for proper fitting. Of the two sheets, one will be used for your racetrack and center/felt insert, and the other one will be the top portion of your rail. Use the best looking one for the racetrack. Grab the other piece (rail sheet), and trace your rail. I wanted a 4" wide rail, so I measured 4" from the outside of the sheet (all the way around). For the arc, simply use the same method as above. Cut the 4" outer ring with your jigsaw. The outer ring will be used for the top of the rail. The inner oval is scrap and can be used to build a second smaller table if you want.
The 4" cut is in progress. Use clamps to hold the wood together while cutting so it won't drop and splinter when you get near the end. Also, you can't see the astericks, but I have two in this picture (one at the end of the 4" piece, and another one at the end of the main table).
Now you need to cut out the bottom lip of the rail. This will come off the other piece of wood (the one you're using for your racetrack). On the 2nd piece (the one that will ultimately be used as the tabletop (racetrack and center/felt insert), measure 1.5" from the outside and draw a line around the table (use your 24" center point to get the arcs). Next, cut out the 1.5" outer circle. This will be the bottom lip of the rail. Remember to mark your astericks so you can align it later.
Now you need to connect the two rail pieces. Turn the 4" piece upside down and lay it on the work surface. Set the 1.5" piece on top of it. Remember to have it facing the right direction (refer to your astericks you marked on the board earlier). The pieces should line up nearly flush. Don't worry about small imperfections, and I wouldn't bother with sanding down the outer edges because it'll be covered in foam/vinyl later. Wood Glue the pieces together and then use your clamps to hold it in place while the glue dries. I'd let it dry an hour or so.