Absolutely, asking a realtor is the easiest answer.
There are some obvious signs identifying homes that are in HOA's while scouting out neighborhoods on your own. The homogeneity of homes in newer neighborhoods can be a sign an HOA is in place. Monuments with a name of the subdivision, landscaped medians, swimming pools and parks are all signs that particular subdivision is in an HOA.
Some older subdivisions appear to be in an HOA, but may possibly be pride of home ownership and an active community neighborhood watch program. There is an older subdivision in South Austin, not in an HOA, that gives out periodic awards for best landscaped yard.
Please do not hesitate to contact me if you have further questions.
Bruce Lewis, Realtor, GRI