Transmission or Power Steering leak?
 

I just purchased my first Audi, a 2001 1.8 A4 with only 125k. Unfortunately I have noticed a leak from under the car. The mechanic mentioned that he believed the seal for the transmission was leaking near the rear of the Tranny, but the color of the fluid I'm seeing is brownish. Also, the power steering motor is whining close to or at full turn.
I'm curious if anyone knows if this sound is common, or other than the dealer, is there a way to check the transmission fluid level? Is the fluid for our transmissions brown? Are these seals a common problem? Any advice or experiences?
Thanks in advanced!