Help please: A Time Capsule question.

I have a 2TB Time Capsule that I set-up as my wireless network. I have my Macbook Pro, Apple TV, PS3, Wii, Printer, and iPhone 4 all wirelessly connected to it. I have backed up my Macbook Pro to my time capsule, but am wandering if I can use my time capsule as a external hard drive also. How do I do this? If not I have an external hard drive connected to my time capsule through the usb port. I can see it in airport utility, but cannot access it with my Macbook Pro. How do I fix this? Also, can all the rest of my devices on my network be set-up to access the stuff I save on my time capsule or usb connected external hard drive? Help please.