My Collecting Issues Or ?

Being relatively new to collecting currency I am really not familiar with what would be considered to be good form for collecting bills.

I have seen the collections of GR58 and jmorgan and many numerous other posters here and have recently started collecting $1, $2, and $5. With ultimate intent of doing $20 and $50 at a later time along with the gold currency.

Some of my basic questions are:

1: Is there a web site that would list the series that have been printed? Is the production could the same for all the districts (not considering the * notes).

2: Is there a web site (similar to numismedia) that could be relied upon or is ebay the most relevant reference of bill value?

3: Do the TPG's have a reference site that would show the difference between grading points like PCGS does?

I have bought some bills from my local coin store, but since being new I have no idea if I'm overpaying. My only reference point is my question: "Do I feel that the price point is appropriate?" So I know right from the start that I am a sheep in a wolf's den. The reason being that I don't know what their product is so I can't research it before I go there.

Case in point: The shop has a $1 Hawaii and North Africa bills that I am looking to buy but don't know if $40 is a good price for the quality being offered. So again I feel that I'm a sheep relying upon a wolf's advice.