Congratulations on your book! Our company, Pump Up Your Book Promotion coordinates virtual book tours. Whether a blog host wants a review copy varies per the host, but they are not necessary to draft interview questions. As long as the host has a link to your site, a synopsis, and an excerpt, that should be plenty to draft interview questions from.
As far as tips go, reaching out to blogs of the same genre or whose topics are similiar to yours, as well as writing and review sites, is important. If your friend who has a blog about knitting wants to host you it works only if one of your characters loves knitting. Maybe people will disagree with me, but I don't believe that any blog stop will do. You can't get by the arduous task of surfing the Internet looking for willing blog hosts, which is one of the reasons writers often hire companies such as ours--they would rather be writing. I don't know when you're planning to tour, but get books out to review sites right away so that they have time to read your book and review it during your virtual book tour. Plan on dedicating at least one hour a day to working on interviews, sending out review copies, and drafting guest articles for your upcoming tour.
And the most important thing--promote the heck out it. Tell everyone you know and use sites such as this to draw attention to your VBT. Consider running some type of contest during your tour to encourage participation.
i agree with cheryl. i just started my tour yesterday. (i'm still figuring mine out) but like anything else, you have to be an active participant meaning making contacts outside of what your promotional person (assumming your going thru services like pump) contacts. good luck.