Help me find the best used motorcycle based on the following
specifications: 1) $1000-1500, give or take a few hundred 2)new rider, 3)
speed and looks not a huge concern, 4) decent mechanical skills in
general, but currently have no knowledge of motorcycle maintenence (so
as much reliablility as possible for the price is important). Please
give me an idea what makes and models I should be looking for on Ebay
or wherever. Thanks.

Used Ninja 250....unless you're bigger than 6' 200 pounds.  Were you
thinking sports or street?

my recommendation would be a Yamaha Virago something in the 920 range.
Its an older bike, but have a good life expectancy.  I started with
this one.