Occasionally, I jump on the forums like this or listen to a podcast. 

Occasionally, it may require contacting a local/county property appraiser office.

With an occasional exception.Like @Basit Siddiqi mentioned, things are more complicated if you're going to live in one of the units.

I've been using MySmartMove (Transunion) for awhile -it's pretty good, though occasionally a pain to use. 

OR, they could be baking cookies for the scout troop, or selling fish dinners for the church occasionally.

I mean there are still sellers out there that wont use a realtor or any other advisor and don't know what to ask for in a buyer. and that allows the buyer with no real financial backing to get into contract.. it happens.. just like bird dog or wholesalers for the houses there are those that try to pimp development land.. most of the times they cant get into contract because they don't have the ability to transact.. but occasionally they do.. the one I am closing on in Oregon in December came from such a person and I paid him 125k in cash for the assignment.. but he worked for a large land development company as a employee for years.. so he knew the game he new the process.. and he got this seller under contract..

Because occasionally, just for fun, I go to an event these people have at some hotel when they sweep through town on their promo tours where they sucker people in with cleverly crafted 1-1/2 hour front room presentations to sign up for a 3-day event, which of course, they use to promote a program that costs anywhere from $15,000 up to $50,000. 

He eats with them, visits, but only stays the night occasionally.

I drive for dollars occasionally, but I don't believe it is yielding enough results as small multi's are not very common in my target areas.  

Occasionally, they have to fill a vacancy for their client.If you want to be a commercial broker, it will take years of working residential.If you want to be an investor, you need to decide what type of investing you wish to start with (buy and hold vs. flipping) and learn about that and start investing.