I highly recommend the video mentioned by tessagin above. Here is a link:
http://www.youtube.com/watch?v=jnke_KzeTI8
It really is very informative, and the subtitles added by her son are rather entertaining to boot! I bought a 4' X 8" piece of plywood that I put on top of my oval-shaped dining table. I can do most large quilts in sections of at least half the quilt at a time. I have just enough room to walk around the table with the plywood set on top of it. It's not the ideal height, I suppose I could put bricks or something under the plywood, but have just used as is. I put an old tablecloth under the plywood to protect the table top. This way I can pin baste, glue baste, spray baste or even use a fusible batting without harming my dining table.