If you want to learn manual targeting follow the tutorial in SH3. Thats what I did...took a while to learn it but in the end I got it...fairly simple...just calculate range, AOB, speed and then check the square box in the target notepad (All is done in the periscope or UZO view).
I remember when I hadn't found out that you have to check the square box...and I went to put all the values manually into the TDC!...those shots shore got ****ed up.
I think the ingame tutorial is the best, all I could find on the net was just super long bibles.