Meta tags can significantly increase your ranks in the search engines. However, they are not the magic answer to promotion. There is no substitute for constantly promoting your site.
(Click Here for META TAG TIPS)
A Spider FOLLOW tag will tell Search Engines to follow the links on your webpage to the next level of pages. If you decide on a NOFOLLOW tag then the Search Engine will not follow & search through any of the webpages that are in links on your webpage.