So there are a few things that should be used:
1. Qbank. A lot of people including myself used Uworld. I mentioned this first on purpose since most of your studying is going to be done by doing questions. After doing a set of questions you go back and reread the ones you got right AND the ones you got wrong. The next step is to go to ------>2. FA (First Aid). It is here that you go to the topics of the questions and review. You literally go "completing" the FA book by adding more stuff to it and writing notes down. 3. online video lectures. There are a lot out there and really depends on which you feel more comfortable with. I personally use Lecturio. They are relatively new and not that known, however, they have very clear and short videos that are pretty much always spot on besides review questions and topics. Here is a link to a video which will exemplify what I have been saying about the: https://www.youtube.com/watch?v=aBvpF0lP4kM
. I have used them for board review as well as just generally for med school since they have vids from MCAT to USMLE2 subjects (pretty much every subject).
As for the video lectures. Some people need to watch all the videos, some need to watch only for known weak spots and others just simply to reinforce topics according to the questions they got wrong. Whatever you decide to do is legitimate. It also depends on how long ago you learned your basic sciences. I am an IMG and needed to have a solid review of the basic sciences since it has been years since I had my lectures about them and thus needed to watch many videos.
On a final note, a lot of people end up using a lot of resources for your STEP prep. Personally, I think that too many options actually end up complicating the situation. I would stick with 2-3 resources.
I hope this helps.