It is easy to let your efforts become scattered and unfocused when you have so many exciting leads to follow. You'll work on one family, receive an email from a relative from another line, get tied up in both of them and then drop those projects for a third. Not only do you forget where you are going, you will forget what is going into your files.
In general, it is a good practice to pick one family at a time: that means a set of parents, their children and the spouses of those children. Gather all the records you have on that family, piece together a timeline of the family members' lives, learn about the localities, and then search for more records. The whole process is easier if you are doing it for one family group at a time. Imagine being buried in different steps of that process with ten families at once.
With that said, it is almost inevitable, once you begin corresponding with other historians, to move around a little bit; but to collaborate with others you must have something yourself, which means you've completed the first steps of that process previously and now you are just looking for more records. So go through the preliminary research steps before you think about branching out to extensions of the family group you are working on.