Organic Nutrient Help

Ok...so, I got these bags that are supposed to be used in stead of a pot? They came free with some mylar that I bought, so I thought I'd try them out and see if they really work, eh? And I'm wanting to go organic, m'kay?

So I got this soil...

Black Gold 100% Organic

Canadian Spahgum Peat Moss
Compost
Earthworm Castings
Forest Humus
Perlite
Pumice

Now, I find myself bogged down in nutrient brands. There's more shit out there than you can shake a stick at (although I've never figured out why anyone should wish to "shake a stick" at anything, but that's neither here nor there, and I digress...), and I can't figure out what I should use, much less what brand, so I thought I'd ask all you dirt boys what type/brand you like using and why.

Can anyone help a girl out?