If you're not finding any great deals by searching websites such as Realtor.com, Trulia, Zillow etc. I would suggest finding a Realtor (I happen to know a good one ;-) and ask them to set you up for automatic email alerts as soon as properties within your buying criteria hit the market. Most websites like the ones listed above will provide email alerts but they unfortunately won't allow you look for specific keywords in the listing descriptions. This is a tremendous advantage that comes along with working with an actual agent.
On the MLS, you'll find property descriptions where the agent can convey to potential buyers all the wonderful amenities that the property has to offer. You might see something like:
"Astonishing 4 bedroom home nestled in a private enclave setting with breath-taking
views of the Connecticut River blah blah blah blah"
So if you're looking for a distressed property to flip, I would suggest asking your agent to send you all new listings that have the following keywords in the listing description:
"Needs Rehab, Needs TLC, Handyman Special, Water Damage, Fire Damage, As Is, Not Qualify For, Missing Copper, Fixer Upper, Investor, Investors" etc
If you're looking for properties whereas the seller would be willing to sell the property on terms such as "owner/seller financing" or "Lease Option", ask your Realtor to put that into the search. If you're looking for a property to generate great income from the start, use keywords such as "Cash Cow, Cash Flow, Instant Equity" and so on and so forth.
Bottom line... If you want to find the great deals, you have to find the properties as soon as they hit the market. Despite all of the technological advances that we've had over the past several years, there's still not a website (that I know of) that will allow you to sift through all of the property descriptions in the same way that you can using an actual agent.
hmmm, I actually own stock in Zillow, maybe I should suggest it to them....
Oh well, for now you can still just use your local agent
:-)