Keep it current.
Besides the danger of having out-of-date information, pages that are updated more often get visited more often, and give you a better chance of keeping more customers. Updating your pages also helps with your search engine optimization and page ranking.
But don’t post for the sake of posting. Find something relevant to say or you will bore your readers and they won’t return.
Correct, posting is a different beast than updating existing pages. Posting means putting up a totally new post. Updating pages means you have gone through your current pages, not blog posts, and made sure the info is still relevant and up to date. This can be done on past blog posts as well though