looking for advice

I am going to be setting up a small intranet server. This server is for a small company with 4 users with windows 2000 as their OS. The server is going to be used for a php-mysql database program and for them to save there files to with samba. I am going to be using redhat 7.2 or 7.3 for the server.  

My question is what do you think is the best way to back up the server (money is a issue, not huge but an issue)?

Is it alright just to put in a backup drive and just copy the user files and the database to it.
If so do I just mount the drive backup and unmount the drive when I am done. I read you shouldn't leave the backup drive mounted all the time.

Now one problem is what happens if the motherboard fails they are going to be down until I get a new board. What if I format the hard drive with a fs that can be accessed by windows2000 and linux. So I could pull out the backup drive and put it on a windows machine until I get the server backup.

Or do I just setup the backup drive on a windows machine and backup to it.

Or what about the server with 2 drives that are mirrored to take care of a hard drive failure and a backup drive in one of the windows machine.

What about what kind of backup strategies... Daily, Increment etc...

I know there is no right or wrong answer I am just looking for advice what other people have done before and whats worked and whats not worked.


Thanks for any advice
Onestar