It can also be a heck of a lot of fun. Take it easy, relax, and remember this is supposed to be fun. Too many groups have lost members over recording a CD, don't let yours be one of them. Before you start, you need to decide as a group if you're doing a CD for yourselves or for other people. If you're intending to sell to people who've never been in your group, you might want to tone that down a bit.
Some people think of a CD as a quick profit.
By the time you pay for the studio and the pressing of the CD and printing of the liners, you're going to be out a few thousand bucks, pounds, guilders, marks, etc. Yes, in the long-term, a disc should make money, but most of your current members will be long gone by then. There have been college groups that've sold out a 1,000-CD run in a year, but that should be a surprise, not an expectation. Choosing the studio. Ideally, the people who record your disc should be people who've dealt with a cappella before.