Here are a few we are familiar with...
-- Boston University Professional Investigation Program (www.professional.bu.edu/programs/professional-investigation/) -- the program director, Tom Shamshak, and the guy whose book it is developed from, Brandon Perron, are both good friends. Terri Brindley, a PPIAC member that may be at the meeting, took the class. Although I have seen the components, she can best answer about it. This is probably the most complete package, and expensive.
-- Criminal Defense Investigation Training Council - www.defenseinvestigator.com. This is Brandon Perron's group with several online studies. This may be geared to criminal, but almost any investigative technique in the criminal field can be used in civil and others. You will find in these studies that Brandon is passionate, almost beyond description.
-- PI Training (http://pitraining.privateinvestigations.org) -- Scott Harrell, who developed this course (very detailed) is also a good friend. It is text-based, comprehensive and covers a lot of material for being in business.
-- PI Education (www.PIEducation.com) is also from Scott Harrell and has approved text-based CE approved courses on specific subjects. Karen and I developed 'Death Investigations for Private Investigators' (www.MedicolegalDeathInvestigations.com) for him and are working on another course for PIs. These are approved in 14 states that require CE.
-- S2 Safety & Intelligence Institute (http://S2Institute.privateinvestigations.org) -- the program director, Tim O'Rourke and several instructors are also good friends. This is a unique experience - a blend of video instruction given with a presentation, a course manual is downloaded. Most of these courses are approved and/or required by FL for licensing.
-- PI Institute of Training (http://www.piinstitute.com) -- the program director, Kelly Riddle, is another good friend. These are inexpensive and approved for the CE in TX.
For books, go to http://pibooks.PrivateInvestigations.org. These include some of the top picks, including those for various certification programs - they are the best of the best and written by the best of the best. Of course, we have to include our own -- Practical Methods for Legal Investigations (CRC Press - www.PracticalMethodsForLegalInvestigations.com) and Professional Investigations: Individual Locates, Backgrounds and Assets & Liabilities (self-published, now an eBook - www.ProfessionalLocateInvestigations.com and soon in softcover exclusively at www.PIBookStore.com, our friends Jimmie and Roe Mesis.
The PI and attorney ethics chapter from our books is so important that it is free - http://ethics.forensic-investigators.com.
You will need a good method, easily adaptable, to manage your cases...
A good package for case management (not software - MS Word based and customizable) is The Case File (Paul Purcell -- yes, another good friend) developed this over 20 years ago and I tested the pilot out, still have and use it. Paul also puts out a good marketing newsletter. http://picasefile.privateinvestigations.org.