Question about repetitive sound.

Hi all.
I'm so excited to finally have an iMac. It's a 24" 3.06 GHZ Core 2 Duo w/ 2 GB Ram & 500 Mb harddrive. I can't wait to have it figured out enough to get rid of my pc!! My question is about a low-pitched "bump" sound that I experience while working on the mac. It occurs every 2 minutes unless the computer is in sleep mode or off. Since receiving my mac on Tuesday of this week the only things I've loaded on it are Office for mac and Skype. I'd like to figure it out before I load Adobe CS, etc. Would love anyone's advice to stop the sound...I'm LOVING this thing, but annoyed every time I'm on it.
Thanks in advance!
~Shine

The only thing that immediately comes to mind are the sounds that may be associated with Mail checking for new emails. That can be set in Mail's Preferences for every minute or every 5 minutes, etc. Could that be it?

Great! Thank you! It was entourage's "no mail" and or "mail reminder" default setting sounds in preferences...It has been almost 10 minutes since I've heard that annoying bump sound! I was about ready to turn off sound all together... I'm feeling a bit lost since I don't know mac at all and am fumbling around trying to work it like a pc. I'll get it and have already seen some great resources here on the forum. Any tips for a newbie?
Thanks again so much!

Just play....and then play some more!
You are gonna love it. I know how you feel about the transition too. We got ours just this summer and it was a huge change (for the better obviously!).
Enjoy the apps that came with your mac too. They are dynamite.
Soon, you'll wonder why it took so long to change over. It will be about this time that you'll also make the proclamation that you WON'T be going back again.

Thanks Randoo53, I know you're right. I've been wanting a mac for years (since we had one when I was growing up!) I already don't wanna go back...but it will take some time tinkering before I'm completely comfortable!
Take care!