it's easy.
The best way is to clone your 320GB (i supposed that Lion already installed in that HD) and after that, clone it to your new 1TB HD.

P/s --> You can use SuperDuper or Carbon Copy Cloner to get the cloning done.

1. You can do a clean install from the DVDs that comes with your Mac. Just put in the new HD and boot from the OS X Install DVD. Very easy one. If you have data on the old HD, put it into a external USB case and use Migration Asst to transfer everything back in.

2. Other way is as the previous post, clone your old HD to the new one. This will be the more appropriate method if you already have data on it.

ps: If you have Lion, you can burn Lion to a DVD and use that instead of the Snow Leopard DVDs that came with your MacBook.

i upgraded it yesterday. using kingston 1333 4gb. cost around rm 69 per stick ! so far no problem with the memtest and i open many apps at a time 

normal 1 xD

kingston kvr1333d3s9 4gb

so far no 

haha, why bro?

correct! not a noob anymore

for those who are concerned about RAMs other than KTA ones not compatible with their Macs, both myself & stringfellow have just upgraded our Mac minis with a pair of Kingston KVR 4GB DDR3 1333Mhz. and it only costs us RM70 each.

am not sure whether does this apply only to new models only or old as well. old Macs are known to be quite picky when comes to RAM.

you can just head to any shops in LYP & Digital Mall. by most, they differ by few bucks per stick.

do remember asking 'em it is possible for full refund or exchange in case the RAMs are not compatible if you are replacing it on your own.

hope this is useful.

the bolded statement will be your answer.