I think the dose is fine - I took either 50 or 100 mg but I've heard of people taking as much as 200 mg.
As far as side effects go, I developed ovarian cysts post-O. It meant I had to take the next cycle off, so it really sucked.
I was worried about the possibility of multiples, so my doc and I decided to try the Clomid, and only inseminate if I had a maximum of two follicles - the chances of twins with two follies is low. On the day of the insemination, I had three follicles that she thought were going to produce eggs that night. We did it anyway - at least in part because they'd already thawed my sperm.
The next day, when I came back for the second IUI, it turned out that four follicles had actually gone, so my chances of twins were pretty high. Nothing took - I'm not sure now if that was lucky or unfortunate.
Otherwise, I didn't notice anything with the clomid. I did have to have a trigger shot that cycle, too, and because of that or the Clomid, I can't remember which, I had to take progesterone post-IUI. The progesterone made me hot and sweaty, and it was summer, so it didn't make me at all happy.
After my experience with the cysts, I wouldn't take Clomid again, but I know it works for lots of people. The cysts are not serious, they're basically luteal cysts, a normal part of your luteal phase that hang around past the beginning of the next cycle. I ended taking the pill for ten days to get rid of them, and they went away, then I had a withdrawal bleed, and off we went again. It sucked, but it wasn't life threatening or anything.
Good luck with Clomid, it works really well for lots of folks.