For a decent introduction to Linux I always recommend looking at the guides at
the linux documentation project
Of course it's best that you would have a Linux box avaible to follow along with stuff. It makes it easier to stick in your head (at least for me).
here is a decent "hands on" introduction to Linux. Shows the basics, introduction to terminology and will give you the ability to carry out basic tasks.
there is the bash guide for beginners Which introduces you to bash and simple bash scripting technics. Most of the administration stuff is taken care of by bash scripts, like the start up scripts are generally bash scripts. Helps out a lot when moving around on the command line.
here is a slightly more advanced guid. It's for Linux administrators and would be good for somebody already experianced with stuff, but maybe in a different OS.
That one teaches basics on how the OS works in general. Gives some hints and tips about what to do and what to look for. Doing basic backups and dealing with services and stuff.
I like tldp.org because it's mostly distro agnostic. What you see in their will be mostly applicable to all distros. Although when trying to figure stuff out it always pays to check out your distro's aviable documentation and look for distro specific howtos on the web incase your distro's maintainers have weird ideas or already setup a way to do some task easily.
There are lots of howtos and guides on the internet. Many geared towards newbies. Some try to be very basic, some try to be enternaining or geared towards "I want it done now and I don't realy care about the why or how" sort of person. Just google around. In tldp there are lots of specific howtos and mini-howtos that will be geared towards specific tasks. Such as getting a winmodem working, or setting up Apache web server.
there is also the linux dictionary
Oh and when you repartition or at least re-format your disk's partitions you wipe out all the files on those partitions (technically) so after you format everything you will be back to square one.
Formatting means to setup the underlyning structure of the filing system inside a partition. Partitioning means to setup the disk into sections that will be used as filing systems by your os. Linux you need a minimum of 2 partitions, root (/), and swap. Swap is used for swap space, that is when your memory runs out of room or whatever it will begin using the swap as "pretend" RAM. In windows this is done in a file inside one of your system's partitions/filing systems. (usually C

. In linux it's kept seperate.
But you can have more partitions. I like to setup a seperate /boot and a seperate /home partition. But it's up to you. But since you already have your partitions setup, just re-formatting them will wipe those files out and you restart there.
Good luck.