It depends how far back you want to go. If you click on the 'sold' button on the left hand side of the page in 'My Ebay' then it will show everything you have sol I think, unless you have deleted the items.
you can only go back by 60 days or last 500 items. It does not matter if you have deleted them you can still view them. Go into my ebay, items sold and then on the right hand side there is 2 windows one for that says period the other one says undo remove just click on one of them and it will undo everything and list all the items you have sold for that period of time.
or you can click on the star for feedback next to your user name, and it will tell you under the feedback left what item was sold/bought and how much was paid for it