The collaboration is based on what you want, they offer three packages of services, which one you choose is upt to you, also depending on what assistance, or marketing you may need. There was always a good and clear conversation between them, so there war nothing bad. And a first talk you always can get for free, so it is up to oneself if you contact them.
Genres? No preferences, have a look at their website to have an own impression. I think romantic novel will be no problem.