[From SQL Server Central
Just about every search result you get for Transaction Log Growth on the internet will inevitably have a result with someone asking how to shrink or truncate their transaction log because it has grown too large. I've even written an article that skims over how to do this for SQLServerCentral.com called "Introduction to the Transaction Log". If you're unfamiliar with the Transaction Log you may want to review this article and my April posting called "A Brief Introduction to Transaction Logs". How about the times you need to grow your log? I did a recent search and had trouble finding a clear cut discussion or article about this.
The article continues at http://www.sqlservercentral.com/articles/Transaction+Log/65255/