It's a great hobby, but it can take up an awful lot of time. I've been tracing mine for 12 years now. It's never really complete as such, as there are always different 'branches' that you can explore. I've stuck really to my direct ancestors, ie parents, grandparents, great grandparents, without drifting off to their brothers and sisters too much, unless I find an interesting one.
Best to start with one side of the family, as you are doing. Start with what you know, then look for your parents parents and so on.
I can't say I've found out anything life changing. My family were all pretty normal with run of the mill jobs. My Dad died when I was young and finding out about his family has made me feel closer to him. Talking to my mum and my Aunts and Uncles about their childhood and parents has probably been the most interesting part, as once they are gone, this information is gone forever.
Ive got back to about 1650 on one side, and 1750 on the other, before hitting a brick wall. It is frustrating when the records aren't there! Ancestry is a good site to use. Be cautious about copying records from other people's trees though, as often these havent been properly researched and can be wrong,
Good luck!