there are a variety of good and bad iron pills on the market. the recommended daily intake for a pre-menopausal (i.e. menstruating) female is 18 mg. you need a little bit less if you've got a lighter flow because of contraceptives, etc. the RDA for pregnant women is 27 mg.
men need around 8 mg in comparison. not losing iron-rich blood on a monthly basis really helps, i think ;)
anyways, it gets more complicated with heme and non-heme iron, but essentially you want to take iron pills that will bring you to around 18 mg. too much won't hurt you, persay, but you might find yourself constipated or loose for the first bit as your body adjusts to the increase in iron.
p.s. i know you didn't really ask any questions so excuse my volunteering answers. i'm one of those obsessive diary readers ;)