You mean the transaction log files of SQL Server?
This normally happens when you set the Recovery Model to "Full" but never make a transaction log backup. For a website you normally don't need transaction log backups (except you have lots of content changing every day, as for e-commerce sites, news portals etc.). Therefore I recommend to set the revovery model to simple, then you can shrink the log files, and make a full backup once or twice a day.
For backing up SQL Server data, I recommend using Ola Hallengren's SQL Server Maintenance Solution, for restore Brent Ozar's SQL Server First Responder Kit.