I'd definitely look into the accelerated BSN programs since you already have your bachelors. But, they're very time consuming and you most likely wouldn't be able to work for the year or so that you're in school.
I'm from Colorado, and I know there are some universities in Denver that offer the accelerated BSN program for people who already have a bachelors. I'd looked into them myself, but I wouldn't have been able to quit working for a year and still afford daycare for my son, so I wasn't able to do it.
Also, my best friend went through a program like that in San Diego. It was expensive and hard, but she went in with a BS in Biology, didn't need to take any other prereq courses, and earned her BSN in a year. She got a job as an ER RN immediately.
So, my advice is to definitely look into the accelarated programs that will build on your BS to get you your BSN. I wouldn't look into the associates programs - they will get you the RN license, but the pay won't be as good as a BSN and there is a LONG waitlist to get into most of those programs (3 years is the average waitlist time here). There are also programs that will take you from an associates to a BSN, but they require prereqs and work experience, so make sure you're asking about the BS to BSN programs when you check with the schools in your area.
Good Luck!