There's a series of books on Highpower shooting by M/Sgt James Owens, USMC. I know they're available from
http://www.sinclairintl.com
And I'm pretty sure that
http://www.jarheadtop.com
is M/Sgt Owens web site.
Most of what basic Highpower shooting involves is what's taught at Weapons Btn, PI. Sling use, (Critical, IMHO), sight alignment / picture, basic position, wind / elev adjustment, trigger control, (also critical), breathing...
If you want to get these, great. If you can find a highpower clinic nearby, I would STRONGLY reccommend taking it. If nothing else, it will put you in touch with other shooters who may be able to offer advice or instruction. Check out CMP's site
http://www.odcmp.com
for a list of affiliated members, and check your state rifle / pistol assn. Someone somewhere should know something.
Basic Marksmanship is one of those wonderful Murphy-isms: the Basic things are always simple...and the simple things are always hard!!
Or you could just join the Corps.