Rental availability is low and rental prices are on the rise. Rents in the area are lower than some surrounding areas mainly because of the number of students and the rents that they can afford. Many properties marketed as rentals and rehabbed to meet the needs of students are priced too high to be feasible for the average investor. Looking "outside the box" when it comes to a potential rental can produce very good returns. Look to smaller homes with 4 bedrooms in need of a little cosmetic work. Stay away from anything that is already investor owned and those properties in need of anything other than cosmetic repairs and homes older than the mid to late 60's. A professional inspection and a competent agent that knows about real estate investing are a must. Caveat emptor!
Being a graduate of UCR I can tell u the demand for rentals in the immediate area outweighs the available homes. Students who wanted to rent in the area were often left looking east to Moreno Valley or room rentals in downtown riverside. As Christopher said you should find a home that isn't already investor-owned as you will pay a premium to have them release one of their solid cash flow sources. However, finding a home that was built before the mid-1960s in the immediate University-area might be a little tough. Hope this helps and if you have anymore questions contact me.