If you find a suitable rental house and you're just not sure of the area my recommendation is to visit the property at different times during the day and see if you are comfortable with the neighborhood activity. Other things to consider for your comfort level; does the property have a garage, is it alarm ready, is there a fenced in yard, do the neighbors have pride of ownership and etc.
The best thing to do it go their yourself, see the area, talk to neighbors, look around on the internet. I won't give you speciic websites as that in and of itself could be a violation depending on the information that is on it or might be missing. There are plenty of good sites around.
Coldwell Banker Gundaker - St. Louis Office