OEM stands for something like Original Equipment Maker, its intended for system builders, as opposed to retail version which is marketed towards home users as an upgrade. As he said, this usually means you just get the peice of hardware, no fancy box or (especially for graphics cards) no extras like a 'free' game. bear in mind that sometimes OEM comes with the driver CD/disk (and manual!), sometimes not, so you might have to DL them and have them on floppy or burn onto CD. for a CPU though, no point at all getting retail.
for a mobo look for KT266A or AMD760/1 chipsets, if you want to be told a specific board you need to say what you want to do with your comp (games?), and most importantly any specific features you want (raid etc) and so on...
personally im going for a Gigabyte GA-7VTXH, a quite cheap KT266A board, if youve got the cash the Asus KG7-Raid is a nice AMD761 board with Raid. There seems to be a lot of appreciation for a Shuttle board on these forums too, look around
I suggest you take a look at mobo manufacturers sites and take a look at their newer boards using the above chipsets, see if the board has what you need. I'd suggest going for a more well known brand like MSI, Asus, Abit, Gigabyte... and take a look at their website to see how much info they give, tech support etc.
can you tell im bored lol
Yossarian lives