As you can see, it's going to be to your advantage to pick an agent and have them do some legwork for you. Probably the best way to do this from a distance is to get a referral from someone you know and trust and have them refer you to a local agent. Next best thing, barring that, is to visit the website of the agents you're considering and see who seems to be the most well versed on the area you are looking into. Riverside is not really my area of expertise, but the areas I am an expert in, outside of where I live, is because i had a client that was interested in that area and I studied it and became an expert.
The slow down in the housing market has had the unintended effect of thinning the ranks of Realtors until we get to the point where you are dealing with a professional that takes their profession seriously and provides superior customer service. That's the only way you stay in business through tough times. There are many qualified Realtors that will be able to help you and supply the information you desire. Talk to a few until you find one you feel comfortable with.
The bottom line about the amount of time a house stays n the market is that if it is well priced it sells quickly. If it isn't, it won't. We are already seeing neighborhoods that have turned the corner where prices have stabilized, but there are still plenty of areas where the prices need to fall a little further before the volume will pick up. Based on a thorough buyer interview, a professional Realtor will be able to direct you to the area you desire and negotiate a fair deal on the property that most closely matches what you are looking for.
It is certainly possible to find a nice home with a nice yard in the price range you have indicated, but which area is more desirable depends entirely upon what your wants and needs are, where you work, whether you have kids, pets, etc.
From now till June is certainly enough time to establish a relationship with a reputable Realtor who can get you information on the areas you are interested in (and perhaps suggest other areas you might also like), send you information and listings, and schedule houses for you to see when you visit. Feel free to visit my website and I'd be glad to help in anyway possible, including referring you to another Realtor if you are more comfortable with that.