I need some search engine advice please

I have several different domains selling reports (ebooks) I do ok, but promoting many different sites, with article submissions, backlinks, posting to blogs, and site maintenance has become a pain. I put up one or two new books a month, and it is just getting too much to handle. I don't like to outsource.

Here's my question. Many of these books are on totally different subjects like saving money, recipes, relationships, depression ect. I am thinking of putting them all on one domain, with a blog, on the same domain. mydomain.com mydomain.com/blog

This way I can put all my efforts into one domain and the sub pages for the individual books, and post to one blog. Also all my promoting like article submissions, free blogs for back links, and such can all be directed at one domain.

Will this work for the search engines? My concern is that I have books on many different topics. I would be posting to free blogs, and my blog with posts on completely different subjects, and submitting articles to the directories in the same way. I would also have long tail keyword links on many different subjects, as the book titles on my home page.

Will the search engines accept this as good content, or punish me for having different subjects on the same site, and blogs? I write all my content that I post on the sites, and in the blogs, so it is not duplicate.

I need to know from some warriors out there, that know more about this than me before I take the plunge.

Thanks Glenn