Does Apple airport express work well?

Sounds like I will try one. I am not a computer tech kind of guy so all I need a wireless card in my PC and the AE?
I am going to run it to a DAC that I am already using the toslink input on. Would I be better off using the usb to the DAC or use something to convert the optical output to coaxial for input to the DAC?

Is anyone using one with a Linksys router. I saw someones review that said you have to have an apple router.

How does the apple tv connect to the network? I think the AE creates its own network. With the apple tv on a network how does the signal get from my computer to the apple tv? Sorry, like I said I'm not a techy guy.