I would suggest this thread. http://hirstarts.yuku.com/topic/3245 I wish that I had seen this 3 weeks ago before I ordered my first few molds.

On top of the 6 for the chess board, I would suggest 50 because it gives a lot of basic bricks like 45 does. Between the two of those you do not really need the basic brick mold. I might also look at mold 60 if you want stairs. 56 gives some pretty cool options including roof pieces and some rather large arches. Really anything in the gothic or castle pages will go well with your chess set molds.

I got both of the pipe molds but have found that they are not the easiest to use for a beginner and plaster is just too fragile for that mold.

I hope that this helps.