Here's a couple of the links that we've found helpful in researching our Press / Blog Strategies.
Blog:
https://blog.etsy.com/en/2012/how-to-pitch-to-bloggers/ (It's for Etsy, but a lot of the advice is solid for Kickstarter as well)
http://tripleseo.com/blogger-outreach/When it comes to finding the blogs, I am SO happy I learned about Buzz Sumo through this Forum - as our campaign gets closer and once it's begun we'll be using the 14 day Pro demo extensively, and likely going Pro for the duration of the campaign. It's just such an easy way to find relevant blogs.
Another trick we're finding fairly successful finding relevant blogs (we start doing the reach out shortly) is simply Twitter. We've begun following as many relevant folks as possible, and making a spreadsheet of which of them to contact with our press release and info. The key here is to be real, and to know who they are. Don't spam - learn about who they are and why they and their network are relevant to your product, and in your mail to them make those things clear.
For Press, we're writing slightly different releases for local media (where "local innovative company does something innovative" type reports might gain more traction) and general media. I've gathered mid week as early as possible but NOT on the hour (e.g., 9:08 Tuesday or Wednesday) is a good time to send out your releases, as you don't get lost in the flurry of emails that hit on the hour, and you're one of the things they see early in the day. Also to time things not too far away from whatever time-sensitive thing is of interest (in our case, a campaign starting, or reaching full funding, or doing something attention-grabbing).
The disclaimer of course is that we haven't launched yet, so all of that's theoretical. I'll report back on the success of those strategies when we can.