I think if you look through the forums, you'll see that most people recommend not doing UW or NBME forms offline. See this post for example
The process is long, but it's pretty straightforward. As far as the step 1 is concerned, just start with your favorite resources for each subject. A lot of people prefer Kaplan because they are a single source for all the subjects and they are pretty good at it, but its your choice and you should pick one resource that works best for you.
When you're done your first read of all the subjects, purchase a question bank and do your second read and qbank at the same time. Then, in the final leg, do NBMEs and UW and it should complete your prep.
After that - you're good to write the exam, ace it and move on to step 2!
If you have any specific questions, please ask, but the hardest part is getting started. After that, you're good!