SEO for a Local search engine site

Hi... I would like to know how to do SEO and online promotion for a local search engine site...( eg :justdial.com ) targeted only particular city as of now.. Its my friend project..

as a start up .. adwords campaign is planned... and he is stuck up how to carry on with On page SEO and off page SEO and boost its online presence. i ahe had ranked some micro niche sites... but dont exactly know how to plan for this type... :-|

BTW outdoor promotions also going to be done... His main concern is online planning ..

would like to hear some suggestions and ideas