Have you checked out at a large local public library branch to see if they have any audio/video learning materials on Spanish? Of course, not all libraries will have this.
the fact that you are considering Rosetta STone for self-teaching, means that evening or part-time Spanish course doesn't fit your schedule? Really do think at some point (maybe after using some freebie audio/video learning aids) to enroll in a course for face-to-face classroom / group learning.
Language learning is a living thing..in the beginning it begs to be experienced directly with other people when one is learning a new language..and another culture "behind' the language in its words.
Or maybe you might discover you have a natural gift for learning another language more quickly than others. Hard to know unless you place yourself face-to-face.
Before I got tested for my French language fluency (or more notably, largely lack of), I signed out and used some audiovisual, reading materials from public library. Very helpful. It had been over 25 years since I used much of any French. But the learning aids refreshed my memory that I passed the basic reading comprehension test (really, that's primary school level), but flunked the written test.It was a 3-hr. test.