I am thinking of going on the pill:
what side affects?
will i put on weight or lose it?
and do i need a prescription from my doc?
Side effects: Depends on the person. These generally are a temporary thing but if they don't go away you can change your pill, there are so many formulations you can usually find something that will work for you.
Weight: Again depends on the person. I am on Levlen Ed and I didn't gain or lose weight.
Prescription: Yes, talk to your doctor about what you need/want it for: I.e. if skin is a problem they will prescribe a particular type/brand. As I wanted mine contraception/lessen pain/heaviness (common basic reasons) I got prescribed a pretty run of the mill one.
Cost: Mine is <$20 for 4 months worth. The price varies depending on the brand you get prescribed, it shouldn't be too expensive unless you end up with Yasmin/Yaz.
Benefits: Less heavy periods, regular periods, can control periods (i.e. skip on on holidays) contraception, good for skin etc...
As you can see it really varies between people as I don't seem to have the side effects that other people on here who have taken my pill have.
Good luck
P.s. read the packet throughly and always tell your doctor/pharmacist if you are taking the pill/other meds and they can reduce effectiveness.