I am new to investing as of last october after the stock market fell very low. I was looking to invest, but then 9/11 happened and everything was pretty scattered for a while. Anyway, I bought some stock before noticing a week later how low cisco had fallen and what a good buy it would be (And it was a great buy for me!). I gained approx. $4.00 on the stock I first bought before selling and buying cisco. What do I have to claim for capital gains taxes? When? How? Do I need an exact amount or can I estimate? Thanks for any help!