help please

i have a executer 2.somthing chip in my x box but have original ms dashboard still on my com
the problem is i want to put a new hd on to my xbox but dont know where to start from
heres the qestions i need an answer too

1 what kind of hd do i buy i see thes a standard internal hd and thers a oem hd i dont know difrence between them

2 what programess do i need

3 do i have to put the new hd into my pc a try somhow make a xox hd from there or do i do it from the xbox itself cas i heard theres a programme called slayers auto installer 2.6 what will make a dashboard straight from x box

4 by the way when i got chip installed it didnt come with any cds or programmes was i meant to get some with it

any help will be most welcome thanks in advance