You should check out Paper Source at http://papersourceonline.com/the-complete-package/ for some basic training, although you should also start networking since the relationships really keep this business well oiled. 

Achieve a long time goal REI full time as my primary source of income.4.)

Also it is easier to source other investors (and hard money as you stated) when you have a LLC, they can become a member and fund projects if necessary.

Even when you hit volume you have to start hiring recruiters and also broker support ( associate brokers ) at your firm to field all the constant questions.Once way,way back I was with Solid Source Realty.

My apologies, I'm still not entirely sure how to quote from more than one source from this thread, but I'd like to add my two cents to the pot. 

You can work with a reputable turn key property provider, or very knowledgeable local real estate agent who also is an investor.Note that the great majority of real estate agents do not work well with investors because they simply don't understand investors and their needs; and they are usually limited to properties on their MLS ( which often is not the source for the best deals).Having invested myself out of state since 2003 I've come to learn what to look for and can talk about this extensively.  

Great source of information!

Also, BP has been a great source of business for me, and all I had to do is what I like doing anyway....just being active on BP, making forum comments, sticking my 2 cents in

Depends on your source of funds.  

You could also use the source you mentioned; especially Craig's list.