How often should I update my sitemap? Is this done manually? Basically I have a google sitemap which I uploaded to 'webmaster tools' a few weeks ago but since then I have added a few new pages and also a blog section with some new posts.

Should I add all blog posts to the sitemap?? Seems a lot of work to constantly manually update it.

Thanks!

I always include the entire site minus admin pages

There are many free online tools for generating sitemap, try to use it

Entire site - but also add a google search to your sitemap page - it helps users find exactly what they are looking for.

You should update your site map after each update page of your website because google loves updated information .