Time Machine question....

I currently backup to external discs using SuperDuper for a bootable image, and then backing up my documents manually.

If I start using Tima Machine, I do not need such regular backups on an hourly basis etc. A weekly backup is fine for me and i dont mind doing this manually.

Can I simply enable Time Machine, do a backup, then disable it again - whenever I want to create a backup?
Will this cause any problems?