my Dell is playing up more and more and thus I thought that getting a new PC might be worth while.
However, I don't want to buy a new but would rather just upgrade my PC.
I.e. new motherboard, CPU, Sound and graphics card etc.
But their might be some problems that I would like to run by some more experienced people - i.e. YOU!

I would like to keep the case, PSU and my RAM. Will this be ok, or will I need to get those new as well for a new MB?

Will any MB fit into the space where my current one is? I was thinking of this one: http://www.ebuyer.com/product/141600
Does the following "USB Ports Configuration12 x USB" mean that it has 12 USB ports or that it is set up to deal with up to 12?
Will my current PSU still work with the MB or do I have to keep my eyes open for something?

Would I be able to keep my current CPU cooler?

I know that changeing these things means that I will need a OS and not just the Dell rubbish.

Is the following shopping list complete or am I missing something obvious?
Sound Card
Grahpics card
RAM (keep the Intel ones I have)

Did I miss anything out?

Sorry if this is basic for you guys but I had a look at a few websites and they make it sound quite difficult, however it really shouldnt' be difficult.

thanks for all your help