Hi Wendy,
Great Question.
About the only "rule" for creating "your" branch of "our" tree is that you provide sources, good one preferably. Beyond that we ask that you follow the Honor Code.
The Style Guide may give you some clues to help you decide on a method.
My methodology changes depending on what I am working on what new tricks I have learned. A wise WikiTreer convinced me to work on single lines with a goal in mind. That helps keep me focused on my objective.
What I often do when I start is to add a short line of about 5 individuals that I have info on. Often just the basic vitals. Then I start dumping source information and tid bits as I learn them. Once I have a few to work with, then I go back through and work on formatting and inline references.
Of course my profiles all look different depending on when I worked on them and what techniques I was employing at the time. Then, over time, I go back through and readdress the older profiles for new and fresh approaches.
Remember, you are encouraged to ask others to join you or help you. We have Sourcerers who love sourcing and Profile Improvers who love to write biographies, and Connectors who love to see profiles get linked to the tree.
Have fun and ask questions along the way.