I used the Ancestry site to do my family tree on my maternal side(my Dad was not British until later in his life, so difficult to do), be aware that when using other peoples input you will find many mistakes, some of my living relatives got things wrong on their pages. It is fun, but without paying for a lot of extras you will hit brick walls and may have to go to archives, libraries and churches to find more accurate details. If you go back a couple of hundred years, some of those documents are really difficult to read, the writing and wording is quite different. Go back further(as I did) and you will need to know a lot of latin too, have fun, I did.