How Do I Avoid Getting Scammed as a First-Time Author?

[florencelotte]

I am done with my book, but I do not know what to do about editing, cover design, and marketing because I have no clue how to do these things myself. I am not interested in doing anything shoddy because this is a book that I really care about. Is there anyone out there who has tried any professional book publishing company and got quality service without being overcharged?