Parking v Redirecting Domains

Hey guys,

So I have bought a couple of domain names, that I want to point towards an existing website.

I am not sure whether it is best to park the domain or 301 redirect, and most importantly how not to be penalized by Google I guess.

What d'yall think out there?
You are better off doing something like this.....

NCR Pads

Create a page on the subject matter of the domain then add a link to the main site. That way the domain is getting kudos on google in its own right and then passing PR to your main website, a 301 re-direct on a new domain does nothing really other than forward to your chosen domain.
I would have said a 301 redirect would be the best option, have a browse around Google's Web documents I'm sure they'll have more info.