You will often find your database log file (.ldf) growing to a very large size, often larger than the databasie file (.mdf) itself.
Log files should shrink after a full backup, but this isnt always the case. Below is a quick command you can run to empty a database log file.
backup log [dbname] with truncate_only go DBCC SHRINKDATABASE ([dbname], 10, TRUNCATEONLY) go
Note: Clearing the transaction log with TRUNCATE_ONLY will break your backup chain needed for FULL recovery. A FULL database backup should be executes right after truncating the logs.