If you have a spare tripod, that is good, as they are steadier than the light-weight light stands. An example of a standard umbrella bracket is a Manfrotto 026. You will need to use one of the "brass monkey" fittings to attach to the tripod's threaded bolt, on which to then mount the 026, and another to attach the flash to the stand, if I remember correctly. (I think the 026 includes the brass fittings in the package.) I nearly bought an 026 last weekend, but decided to do a bit more research first.
There are other brackets; I am considering a Lastolite Triflash, which holds up to three flashguns and an umbrella.
When I have used remote flash on a second tripod thus far, I have not used modifiers, but inspired by Syl Arena's and Joe McNally's books, and tutorials videos from Joe McNally and Zack Arias, plus some local coaching by Sonny of the Pixtus forum, I am about to start.
