I've done quite a bit of my own family tree so far and there are a lot of free resources out there, but you need to know where to start otherwise like you say it becomes a bit confusing and overwhelming.
Basically, start off with everything you already know - talk to relatives and start simple - with an outline, so start with you and go backwards, write on a piece of paper, don't worry about date of births yet - just write down names, you, parents, their parents etc - until you have an outline and then start filing in the details.
Start here...
http://www.bbc.co.uk/history/familyhistory/index.shtml
It's a good site for beginners and will give you all the basics - watch the video "How to get started".
This site is essential, massive and free...
http://www.rootsweb.com/
Then there is the LDS (Latter Day Saints) archive - this is incredibly helpful and allows you to search censuses that they have indexed...
http://www.familysearch.org/
You will be able to make a very good start with a little effort, and it only becomes very difficult when you go older or start to do the living history, then you need to visit the FRC (Family Records Centre) and the PRO (Public Record Office).
It also depends a lot on where your ancestors came from - I have some Scottish relatives and the Scottish records are the best I have seen, all online searchable for a small fee (you buy credits on the website). English records are not as good, and tracing my Irish ancestors is extremely hard going (most of the records were destroyed in a fire in 1922).
Overall, start simple, don't get overwhelmed and don't be afraid to ask, either on here, or rootsweb forums is a good place. It will be very rewarding believe me!
If you have anyone you'd like me to check out then post their details here and I will try my best.
Good luck!