Hi chance:
Welcome to the addiction.
All of the above...and...
Paul Hogel's SA tutorial at
http://www.lakesidetrader.com/sa.html will help you understand dagger terminology in general...and...
If you're too cheap to buy reference books, (like I was)
you can become familiar with the characteristics of edged weapons by viewing Wittmann's inventory descriptions at
http://www.wwiidaggers.com/inventory.htm He has good photos, so you can see what you're reading about.
Just remember that the ammount of information on this stuff can be overwhelming. And, new things are discovered all the time. Pick a narrow field at first, than branch out gradually. If you take it in chewable bites, it can be fun. If you try to take it in all at once, your head will explode.
Good Luck!