A lot of people are very much against circumcision these days and I'm sure you will find lots of people here who can explain to you the reasons why.
My own situation is that my husband is circumcised (and very happily so), and he wanted our son to be. So we had our son circumcised. Afterwards I found some stuff on the Internet claiming it was mutilation and all that, and I started to feel horrendously guilty, even though at the time I thought I was doing the best thing for my son.
But eventually I realized that although it might not be the way nature intended it, it's not the end of the world either. My husband is perfectly happy with his circ and we have a great sex life. Furthermore some men who have been circumcised later in life (by choice) prefer it that way. (You can read the personal stories of such men here at this sitehttp://www.circumcisioninfo.com/
According to some things I have read, approximately 5-10 percent of males who are not circumcised have to be circumcised later in life due to problems with the foreskin. Advocates of circumsision point this out and say it's better to avoid these problems; critics say "why fix what isn't broken yet?"
Some studies also show that circ'ed men have less of a chance of catching STDs, including AIDS, although critics have pointed out flaws in those studies (sorry I don't know the details.)
I can see both sides of the story actually, and I don't see myself as belonging to either "camp." I feel that circumcision does have benefits, but that ultimately it should be the boy's choce. I think I would have felt better if my son had had the chance to choose if he would be circumsised, as an adult.
I think it's important for you to do lots of research Jodie, so that you can make an informed decision when your son is born.
Regarding pain, no physician worth his salt would ever do a circumcision without freezing the area first. My son had an analgesic cream, and the doctor was very careful to make sure the cream had had enough time to work before she did anything. And she said that during the procedure he didn't even cry.
As I said, just make sure you get a lot of info before you make a decision.