Hi Lukas,
This is a very broad question, one to which there is no simple answer. You need to ask yourself "what kind of a market would want my services?" and search for bloggers within that market that have a decent DA (although not an accurate measurement currently due to Moz updating it, should have it's accuracy returned in November).
Use a tool like Buzzstream to collect these blog sites and let the software dig for the contact info. From there reach out to the individual bloggers and see what they would like to write about your services. I would steer away from straight up offer money, but they might something in return, maybe a social push or some advice about the service you offer.
I hope that helps.
