http://www.wikitree.com/wiki/How_to_use_WikiTree#Adding_Information
The help files on WikiTree are very good. They take you step by step through the process of creating your family tree. If you get confused you can always post a specific question here in the G2G forum. Specific questions are apt to be answered much more quickly than generic questions such as "Who is the father of John Doe?" A more specific question would be, "Who is the father of John Doe born 1820 in South Carolina, married Jane Sample, father of ...." It's also an excellent idea to post a link to the profile in question. If you're not sure how to do that, an easy way is to go to the profile in question and just copy the link from the address bar in your browser and paste it into the question box that appears when you type your question (which should really just be a brief synopsis of what your question really is) into the box which says, "Ask our genealogy community a question and then hit "enter."
You should get a mentor soon who will help with any other questions you may have.
I hope you enjoy your experience here on WikiTree and I wish you good luck with your research!
Denise