You will be going through the pipeline for about 2 years, so by the time you finally get to your submarine, you should be all up to speed. That being said, I know you're probably excited about going to bootcamp and getting things going, so I'll give you the run down.
So as a submarine electrician your job will consist of three main things. Standing watch, doing maintenance, and qualifying to stand watch or do maintenance. When you first show up to your boat you'll have already gone through about two years of training, and quals shouldn't really be a struggle. You'll be handed a stack of qual cards and told to "get hot".
Watchstanding is pretty straightforward. For 6-8 hours at a time you'll be roving around taking logs and cleaning or sitting in front of a panel and taking logs. Sadly that description doesn't really do it justice, but trust me it can be pretty exciting. You'll learn a lot more about watchstanding as you go through the pipeline.
Maintenance is basically fixing motors, cleaning motor controllers, fixing random electrical equipment, and ESPECIALLY cleaning out your SSMG's (if you have them) Some of this is really boring follow procedure and put a check in the box, but troubleshooting a fault and fixing broken electrical equipment is one of the most rewarding parts of the job, in my opinion.
Qualifying is just learning what you need to know about something, and proving that you know it to the right people. If there's anything that you should take away from the pipeline, it's how to learn, because you should never stop learning while you're in the Navy. You'll keep taking exams to keep your level of knowledge high, attend divisional and department training at least weekly, and you'll continue to qualify hopefully the entire time you're in the Navy.
Best of luck at boot camp, keep your head in the books in A-school and develop good study habits. If you have any more questions about being a submarine electrician, I'm pretty active on here and always willing to help.
-EMN2