Wind is viento, but some sources tell me that windy is al viento or
hacer viento, but others say it's ventoso, defined as windy(tiempo)
(whatever that means). My question is, what is windy (as in lots of
wind outside), and what does ventoso mean.

Todo ayuda muy apreciado!

Patrice

Numerous sources found by searching google for ventoso Spanish
dictionary seem to imply that it does indeed mean windy. I saw one
other source which said it meant "wind-wafted" which I suppose is
slightly different.

Here is one source ("find" or scroll down to windy)
http://www.probertencyclopaedia.com/dic/eng-sp-w.htm

Here is the definition of ventoso at another source:
http://yahooligans.yahoo.com/reference/dict_en_es/entry?lb=e&p=num%3As22615

hacer viento is another way of saying the same thing, but with a
construction of the verb and the word for wind, instead of the actual
word ventoso which means windy.

Although ventoso is a correct way of saying "windy", I would opt for
"hace mucho viento" or the proper congugation of that depending on the
context.  "Ventoso" is also well known slang for "fart", ("se tiro un
ventoso" = "he passed gas") so I would stay away from it when
describing normal wind.