Please help me out to Increase the page rank for my newly developed sites related to ,food,travel,Medical.
Very funny Anyway, you would need to submit your link to as many web directories as possible. You should also buy/exchange links. We can give ideas but you have to do the work.
You can also try the forum posting, RSS submission, article submission, and as what "ablaye" said the Directory submission and link Exchange. But in link exchange you need a lot of patience also you need to collect the sites which is relevant to your site. You'll going to email them asking of link exchange but there's a one tip if you want the fastest reply you need to add them first to your site before you email them. and give them enough time if they did not answer it's enough time for you to remove them in your site. Goodluck