Ok I have alot of subdomains.One of my subdomains forum.googleandroid.info is going great in the search engines and now I just created alot of subdomains and put forums on them. They are: iphoneiphone.googleandroid.info programming.googleandroid.info makeawebsite.googleandroid.info hiphop.googleandroid.info So it should be another 2-3 days for these sub-domains to be indexed by google,so do you think that these subdomains will do better in the serps,as opposed to buying a new domain name and putting the sites on them? I'm hoping the "make a website" subdomain forum ranks very highly.
It's no different than starting a new domain, except sub-domains are harder to obtain links for, be accepted in to directories etc. So a fresh top level domain targeted for your site is best.
Subdomains have no difference for SEO compared to domains but are harder to market (word of mouth method). You might want to check these two articles before choosing subdomain/name: how to tell when to use dashes and using common words in domain name
Before using any subdomains, you have to read more articles about subdomains. Do not use before reading articles.