File server and backup - where to start???

[HiDeHo]

hi all I think its about time I set up a backup server so I can do backups of my os, store media and files on. etc. what options do I have.

I probably dont need something to big, or expensive.
I see 2 options just plugin a hdd to my macbook and use it for backups etc
or using a fileserver??? and will probably need

1. a hdd for backups (i understand powered is best for this)
2. a file server to plug the hdd into my network.

My router does have a, very slow, network fileserver which I could use to begin with. I have an old 60gb laptop hdd attached to this with external power atm and when i imported the media on it into itunes it took a a while.

So any ideas as to what i can do. I consider all options weither apple or other brands that work well for what i am wanting to do.
Thanks in advance