new "used" bike, what pedals?

Go clipless for sure.

The shoes will have 2 or 3 holes (I'm not sure for Look) and they can take any of the clips that use that number of holes to attach.

I suggest going ahead and investing 100-300 on a trainer while you wait on your bike, and put it on the trainer as soon as you get it.  Just to give yourself a chance to practice clipping in and out.  Besides, you will want to do some of your riding inside before long anyway.

ETA: Since your new let me clarify.  Clipless means no toe clip.  But you still "clip in" on a clipless pedal". 

There are many choices in clipless pedals and while no clear winners, each have advantages and disadvantages.  I have used Look and SPD, and for several years now I've used Shimano Ultegra PD-6700s on both my road and tri bike.

Here's why:

Walkable on road shoes without covers (unlike SPD or Speedplay)
Don't slide on wet pavement (unlike Look)
Don't fill with mud (unlike Speedplay)
Wide platform (unlike SPD)
Adjustable float (unlike SPD)
Easy to clip in (unlike SPD)

I spent time a while bike evaluating a switch to Speedplay, and decided against mostly based on the mud and cleat cover problem.  Lots of people have reported problems with the cleats filling with muddy grass when running out of T1 to the bike mount location.

Walkability is important for me.  I don't want to have to use cleat covers to walk into stores etc on my rides.  Shimano cleats can be walked on without worry of slip-and-fall (unlike Look's hard plastic cleats), and don't destroy people's floors (like SPDs on road shoes).  With Look cleats, I fell over once at a stop sign when I put my foot down on a wet metal plate without noticing it, and my foot just slid sideways and down I went.

Years ago with my Looks I'd always forget to take off my cleat covers and the group ride would take off and I'd have the doh! moment of trying to clip in wearing covers.  No covers = one less thing to buy, carry, forget about.

We bought my wife SPD for her road bike because they have those at the gym on the spin bikes, and we regret it.  She found it too hard to clip in and out, and the double sided entry didn't offset that significantly.  The only advantages of SPD are low price and how common they are on indoor spin class bikes.

Some useful old threads on the subject:

http://www.beginnertriathlete.com/discussion/forums/thread-view.asp?tid=248586

http://www.beginnertriathlete.com/discussion/forums/thread-view.asp?tid=251003

I have to disagree with you on the looks. You can get cleats with rubber grips on them. I have had mine for 4 years and never had a slipping issue or felt the need to use cover. I love Looks and will probably never use anything else.

Well so you can now!  http://www.biketiresdirect.com/product/look-keo-grip-replacement-cleats

"New Grip rubber pads making walking easier without the need for cleat covers."

I've very happy you corrected me on that.  I want to buy a Garmin Vector pedal-based power meter, and that uses only Look Keo pedals.  I can get the Garmin Vector pedals, and those Look cleats with rubber pads, and not have to compromise.  Yay!

The answer is "clipless pedals".

the only decision is 'which model'.   read Tom's overview.  he does good review

http://university.tri-sports.com/2011/09/09/beginner%E2%80%99s-guide-to-clipless-pedals/

I am giggling at the image of a P3 with platform pedals on it.....    

Seriously, go clipless as others have said. Pedal choice is very personal and there are lots of variables to consider.

Typically there is a very short learning curve in going clipless. Yes you will fall a couple of times. Think of it as an initiation to the club!

Enjoy your new bike.