Giant riders..not the brand either

[Trek420]

BTW, welcome to TE!

A) as a humongous women should I just go with any bike that fits or does it really make a difference for fit with female specific bikes?

Most WSD bikes whether road or mountain have the short or shorter rider in mind. That does not mean you won't need one or even aspects of WSD with a standard mens bike. Have you had your bike fit to you? If you're feeling clumsy that could be why you feel that way and not just because of height. Best to check with a local shop.

B) are there any good books I should read or workshops I should attend? I'm in Portland, OR

Portland's very bike friendly. Ask at your LBS (local bike shop) which clubs they recommend. Check the clubs schedule for rides listed as "no drop". Those will be more newby rider friendly, supportive.

You also might find or start a ride here! Check the regional section to find TE members in your area.

http://forums.teamestrogen.com/forumdisplay.php?f=51

C) Anyone know where I can go ride and crash (I'm pretty damn clumsy being a giant) without too much mockery or concern? I have other questions but they'll come up over time.

I'm a roadie, so I don't ride to crash although MTB'ers may seek that out. I refer you to answer B for rides for new/newer riders.