fellows i am doing seo since 2 3 months before but still my site is not shows in in google serp ranking, what should i do.. to get ranked in googles serp

Do directory submission for your website in high PR site.
Do social bookmarking for yor site
and use more offpage technique and use use unique content in your website, its really helps you.

Try to concentrate on keywords thet you want to rank on the Google. using that keywords in High PR directories, social bookmarking, Press release as well as article submission. make use of the keywords inside your site i.e on page seo. Generate more backlinks on thet keywords then only it going to be ranked on Google.

Always do submissions in high PR websites. Do Directory Submissions, Social Bookmarkings, Forum Posting, Blog Commenting, Article Submissions, Press Release, etc...

simple ways you create dummy blog and review your post

Do link building in high PR and domain authority web sites. wait upto six monts to get rank. some competetive keyword will not come easily.

Try to build back links with same theme based sites because it's most valuable part in link building.