My advice:

1. Know the database schema.  Understand what tables and what fields in those tables are key and how they relate.  This extends to both transactional data and metadata.  If you want to understand the application, understand the database.

2. Practice.  Get involved with FSM projects right away, even if your are doing small pieces.  Stick with it.  You have to build up over time.

3. Be patient.  See #2.  Give yourself time to assimilate and practice what you learn.  It literally takes time for your brain to organize new information so you can use it.

 

I would add that I have found it helps to get a view on how the system is actually used in live environments as early as possible. As FSM is highly configurable the setups that are actually in use tend to differ greatly from what the documentation would suggest. 

Understanding the business rules - being able to interpret them and how to create new ones as well as amend existing ones - should help a lot as this is where most customer specific amendments are driven from.

The other area I would recommend looking at is the sync rules and how they replicate down to the devices. A minor change to a sync rule can have a major impact on system performance due to the change of data being driven to each mobile device. Understanding this area will greatly assist in fine tuning the performance of a system setup.

Hope this helps.

1. when you press F1 in most of the screen, you will get Help document of those screen and littlebit head-up of what is it and how to work.
2. there are few documentation are delivered with installation you can follow those as well. ( i have attach those for your easy perusal)
3. you will get better understanding while working and when you have a Training for functional and Technical