Will this boost my search rankings? For example. If I were to 301 redirect some of my established websites with good rankings in the search engines to my main website...would this boost my main website's rankings?
why would you 301 redirect all old established sites just to get link/serp boost? you can just link form those sites to your site and get backlinks that will help your site to get the serp boost. purpose of 301 redirect is to permanently move an old site to a newer version site. not to get backlinks from older site to new one. you can still have your old sites and benefit from their existing ranking and traffic but link from there to your main site to get backlinks