reduce size of the wss content database LOG

– Truncate the log by changing the database recovery model to SIMPLE
ALTER DATABASE WSS_Content
SET RECOVERY SIMPLE;
GO
– Shrink the truncated log file to 5 MB

use wss_content
DBCC SHRINKFILE (WSS_Content_Log, 5);
GO
– Reset the database recovery model.
ALTER DATABASE WSS_Content
SET RECOVERY FULL;
GO

NOTE: Don't leave ur db Recovery in SIMPLE mode...this will cause some problems when u try to delete site collection from sharepoint central admin.
ALWAYS keep it in FULL mode.