Processor Speeds

[croden]

I'm going to be putting together a new semi-budget build for myself shortly...I used AMD on the few builds I've done before and never built with Intel but the prices for the performance at Intel right now are just too attractive to pass up. I am getting a little bit confused by the Core 2 processors, from what I am reading it seems that even though the speeds listed for the Core 2 I am looking at are lower than a cheaper Pentium D, the Core 2 is still the better processor. Is this right? Which of these 2 am I better off getting?

Intel Pentium D 945 Presler 3.4GHz LGA 775 Processor Model BX80553945 - Retail

Intel Core 2 Duo E6300 Conroe 1.86GHz LGA 775 Processor Model BX80557E6300 - Retail

The Core 2 has what appears to be a much lower operating frequency...but I see in these forums it is more recommended than a Pentium D with higher speed. What am I missing here please?

Also, since I've never used Intel before, what is a good mobo to go with that Core 2 or Pentium D? I don't want a cheap motherboard, that is one of the components I am willing to spend a little on.

Thanks for any direction.

[flanzig1]

The Core 2 Duo uses a new architecture that is more efficient than the P4. So the Ghz rating isn't that big of a deal with Core 2 Duo.
A starting mother board for C2D is the Asus P5B