This is an outstanding article on church discipline written by Jason Harris. I encourage you to go to the site and read it in its entirety. Also be sure and read two of the comments – one by Jonathan Leeman and then Jason Harris’ response to Leeman immediately following Leeman’s comments. Leeman is the “go to man” on church discipline and church membership in the 9Marks organization, and an elder at Capitol Hill Baptist church in Washington, D.C. which is pastored by Mark Dever. I have witnessed enough abuse of the disciplinary process promoted by 9Marks at UCCD to realize that the 9Marks application of discipline is seriously flawed. I found myself strongly agreeing with many points Harris made. I believe what he advocates would restore some much needed sanity to the church.
Update: Here is a recent article by Carl R. Trueman on church discipline which dovetails nicely with the subject matter.