Commuting - What not to wear!?

I commute about 12 miles. 12 miles beach route (for the road bike) and about 9.5 miles on surface streets (with the BMX). I live in Los Angeles and since it's still summer esque it can be hot. It's moderate in the early morning, but if I have to commute mid day it's horrible. I bring a change of clothes every day and change out of my sweat ridden clothes every day. Problem is they are normal clothes since I've never been into commuting it's all I got...

What apparel can I wear to reduce sweat as much as possible and where can I get it, blah blah etc.?
Thanks.

i find that I will sweat the most when I stop riding, so really nothing will prevent you from sweating. I wear jeans and a regular t-shirt on my 5 mile commute, and change out of them during the day and change back when I ride home. I see no reason for anything special on my commute, but on any rides over 30 miles I wear giordana bibs.

I also commute in jeans and an undershirt. But don't they make sweat absorbing lycra suits these days?

there are tons of companies that make wicking clothing, most kits (ie roadwarrior spandex) wicks sweat away from the body if ya wanna feel drenced cotton is the way to go, want to get rid of that feeling go with a wicking fabric

Cotton sucks, IMO. I always wear bike shorts and a wicking T. Besides being more comfortable, they'll dry while you're working.

Buy the shorts online or at a bike shop. Buy the Tshirts at your favorite discount department store. I like bright colors for visibility.

OMG, yeah cotton blows.

Bike shorts (don't wear underwear underneath!) and you can get baggy mountain bike shorts with pockets if you don't want the tight spandex kind.
On top wear something sweat wicking, not cotton. You can get cheap shirts at target, walmart, etc... but all that synthetic stuff will stink. If you have the cash, look for micro-weight merino wool. It wicks at least as good as the synthetic stuff, dries at least as fast, and it doesn't smell like body odor, even after wearing it several times without washing. I have some from SmartWool and Ibex, found on the net for about $50 each instead of $80-90 retail. My only complaint is it's hard to find brighter colors.

I buy poly wicking shirts from alertshirt.com and bike shorts from love2pedal.com - I have historically used regular cycling shorts but I think I'm going to change to baggy shorts.

I wear cotton shorts occasionally but I sweat even in the dead of winter when I dress lightly enough that my skin is almost blue when I get there. I exercise, I sweat, end of story, so I really want some poly clothing. Cotton feels so nice, but it's miserable when wet.