Newbie tips, what mods to get?

Hello all,

Just received a free copy of Silent Hunter 3 from Steam as I preordered Il-2 Cliffs of Dover. I am really looking forward to play this game, but am total newbie and don't know where to start.

What mods / if any / should I install to SH3, or does the game play fine straight out of the box for a newbie?
I would like to ask also that is there some good manuals that I should get online?

I also own Silent Hunter 4 and U-boat missions expansion that I bought year ago but never started to play it. Should I get into SH3 first before going into SH4?

Best Regards.