
here's the mitten i just made this morning, and here is the pattern, which is probably enough to go on. if it's not, there's a much more detailed (and picture-ful) tutorial over at my blog.
ETA: the yarn i used was sean sheep's "maldon", with a 6mm hook. if you're going to use a yarn that's that thick, i'd recommend going up to a 6.5mm hook and seeing what happens.
ETA (again): worked continuously in spiral rounds, until just before the ribbing starts. instructions are in the pattern. read carefully.
MITTEN
R1: 5 sc in magic ring, pull tight (5)
R2: 2 sc in each sc around (10)
R3: 1, 2 sc around (15)
R4: 1, 1, 2 sc around (20)
R5 & 6: sc around
R7: 1,1,1,2 around (25)
R8-20: sc around (25)
R21: sc in first sc, ch 10, sk 3 sc, sc in next sc, sc around
(total of 22 sc, plus 10 ch = 32 stitches)
R22: sc in each sc and ch around (32sc)
R23: sc in first sc, sc2tog, sc next 6 sc, sc2tog, sc around (30)
R24: sc in first sc, sc2tog, sc next 4 sc, sc2tog, sc around (28)
R25: sc in first sc, sc2tog, sc next 2 sc, sc2tog, sc around (26)
R26: sc in first sc, sc2tog, sc2tog, sc around (24)
R27: sc in first sc, sc2tog, sc2tog, sc around (22)
R28: sc around (22)
R29: sc around, join with sl st in 1st sc, ch2 (22)
R30: dc around, join with sl st in top of ch2, ch2 (22dc)
R31: fpdc around, join with sl st in top of ch2, ch2 (22)
R32-34: fpdc around, join, ch2 (22)
R35: sl st in each dc around, fasten off, weave in ends
THUMB
R1: 4 sc in magic ring, pull tight (4)
R2: 2 sc around (8sc)
R3-9: sc around (8sc)
R10: 1,1,1,2 sc around (10)
R11: 2,1,1,1,1 sc around (12)
R12: put the thumb and mitten together, and sl st each sc in thumb into the hole in the mitten, both pieces right side out.
it's awkward (both to do and to explain), but it can be done.
alternatively, you could do a final thumb row like this: [R13: sc around (12), fasten off] and just sew the thumb and mitten together the old fasioned way, but i've been getting really into NOT sewing, but actually crocheting stuff together. you'll see, when i finish the wizard of oz gang.