FamilyEcho.com is a great, free tool to create a family tree. You can zoom in to see much bigger pictures, change the view to see maiden names–or not, and much more. Be sure to check out the Partners tab to see information about a Sims’ relationship and the Biographical tab to see more information about a Sims’ background.
The family tree is quite large now, so when you click on a Sim, it may shrink to just show that one family. To get back to a broader tree, just click on a Sim from a previous generation to expand your view. Enjoy!