This is a pattern I made using my mother-in-law's instructions for making circles.
Crochet Circle
Round 1: Using an adjustable ring Ch 3. 11 dc. Join with sl st to top ch of ch 3.
(http://www.crochetme.com/forums/t/28917.aspx)
Round 2: Ch 3. 2 dc in each dc around (24 dc). Join with sl st to top ch of ch 3.
Round 3: Ch 3. (2 dc stitches in next dc, one dc in the next dc) continue around. Join with sl st to top ch of Ch 3
Round 4: Ch 3. (2 dc stitches in next dc, one dc in the next 2 dc) continue around. Join with sl st to top ch of Ch 3
Round 5: Ch 3. (2 dc stitches in next dc, one dc in the next 3 dc) continue around. Join with sl st to top ch of Ch 3
ontinue with the pattern until the circle is the size you would like it.
Finish off (I used invisible finish), weave in ends.
* the first Ch3 of each row counts as the first dc for the round
From the expert: "Basically to get the circle to lay flat increase in every stitch on the first row, increase every other stitch on the second row, every 3rd stitch on 3rd row and then after that increase as needed to make it flat. I usually like to slip stitch the first and last stitches together and I usually mark this with a marker (little safety pin or whatever) Some patterns have you not hooking them together and turning on each row. I don't like this because you will have to have a seam."
I'll post a photo later, I have to run. If you want to sew two together use the crab stitch.