Does it help to have other domains I own redirect to a Main site I run? I have the site in my Signiture as my main site. Its a social Netwokring site for Adults and I have 3 other domains that I am not using that are adult in nature and they are redirected to this site. Does that help or should I just park them and make revenue that way?
No but it also depand where are they stored/placed..on the same server?? Google check also IP adresses of directed web pages
Short answer: No. Long answer: Well, technically it depends on what you need to do. If you need SEO effect, then no. Google will discount pages without content and that only redirect to another website. This is common sense. If you are redirecting traffic to a new domain because of a domain transfer, then yes this will tell all of your "old" visitors where to look to find your website again.
My opinion is that it is ok to do, however, it will not get you better rankings. The reason you seem to be doing it however, does not seem to be right according to the Google Webmaster Guidelines. Google is not yet able to read the minds of webmasters however you should know that Google only wants the best websites on top on their index, not because they want it but because we all (that are using Google) want it. Do you think your website deserves a number one spot, above the ones that are currently listed in the top 10? If you can say yes to that, you can use SEO in the right way to make the information on your website better findable and it will then be for the people to decide if they also think that your website should be number one. Google does not only look at your website, it also looks at what users want to find.