I would start with auto targeting until you get bored. Then try manual targeting, which is a challenge. Around that time you can try a supermod. Take your pick of FOTRS (Fall of the Rising Sun), RFB (Real Fleet Boats), or TMO (Trigger Maru Overhauled). Run Silent Run Deep (RSRDC) is an overlay supermod for RFB and TMO that tracks convoys and task force routes in the war, so if you want to participate in major sea conflict in the Pacific, get your boat to location at the proper time and place, and viola, the naval forces participating will be there as scheduled. Webster's has amassed many game fixes for the stock game into a mod call GFO, but I have never used it.
To master manual tareting, you will need to understand the TDC (torpedo data computer), and how the Attack Dials (TBTtools) work, including the concept of aspect ratio. Playing at full realism is not easy.
A useful mod for manual targeting is the Easy Aob mod. A stand alone program that is very good is gutted's Solution Solver.
Max Optics and SCAF (Ship Centered Accuracy Fix) are useful too.
There are a wide range of individual mods ranging from medals fixes -to pin-ups for the office desk photo -to great white sharks prowling the waters (I haven't seen any) -to super torpeodoes that will sink any vessel they hit.
You can find mods in the Mod forum for SH4. In the main SH4 forum, Rockin Robbins thread re the Skippers Bag of Tricks provides much useful information including links to attack techniques, avoiding radar, etc. Plan on spending some time reading. The above is merely a start, as there is a ton of material. The sim is complex, and if when you want to be blown totally away, go to MoBo forum and takle aaronbloods MoBo (electronic manuevering board) masterpiece.
Welcome aboard.
