I am somewhat new to flying and considering buying an airplane. But
with all the ADs/SBs/etc. out for all kinds of airplanes, I was
wondering if there is somewhere online I could go plug in the type of
airplane - C182, and serial number - 18281234 and get a list of all
outstanding ADs/SBs/etc that the airplane is subject to.

The closest thing to what you are looking for is this:

http://www.airweb.faa.gov/Regulatory...e?OpenFrameSet

Unfortunately, it's not as simple as searching by airplane serial
number. You need to make an equipment list - Airframe, Engine,
Magnetos, Prop - there is even a transponder with an AD against it.
Also, forget serial number - you will have to read the AD and determine
if it applies.

SB's won't be there, but they're not mandatory for Part 91 operation.

There is commercial software to do this as well, and I've used it - but
I don't find it to be any betterat the task than the FAA's free search
engine.

The real problem is not finding the AD's, though. The real problem is
determining applicability. Was it done? Does it need to be? Unless
you trust the guy who did the last AD search, you will have to go
through the logbooks, working backwards, to make sure each one was
done. What's more, there is such a thing as paper compliance. I owned
an airplane that supposedly had a fuel line replaced per AD in the
1960's. When I removed the fuel line, it had a 1950's date tag.

Whichever way you do it, a comprehensive AD search takes someone who is
experienced at it (he might or might not be an A&P, and an A&P may or
may not be experienced) at least two hours, and that's paper
verification only on a simple fixed gear airplane. It goes up from
there. Not knowing what you are doing, you might manage to get it done
in a day if you have help. Your chances of figuring it out on your own
are slim.

Michael