I've just turned on the new Tags feature as well as an enhanced Advanced Search. You can tag any book from your (now wider) bookshelf, and sort by tags right in the bookshelf. There's also a new Tag page under 'Browse' in the top menu. On the left menu of each title, you'll now see a tag list also.
Advanced search is available by clicking 'Search' on the top menu. You can search by cuisine type and course as well as choosing to search in different ways (all words, exact word and exact title).
We don't have tags for individual recipes. That will be coming when I figure out the best way to implement it - perhaps as an ingredient list more than just tags.
Let me know of any bugs here. I've already noticed that tags don't show up yet on Magazine pages. This will be fixed soon.