Hiya,
I live in Croydon, and have been in and around the area all my life (apart from one breif stint in outback Queensland, when I was too young to know or care about property prices!).
Drugs are still an issue in most of that area; Ringwood, Croydon, Mooroolbark, Lilydale. Similar story down the Belgrave train line as well, Bayswater, Boronia, Ferntree Gully in particular. I remember about a year ago, I had to take a train somewhere while my car was out of action. Sitting and waiting in one of the covered seats at Croydon, a syringe fell on my head. Haven't sat under one of those since (nor have I taken many trains, either, but that's a lifestyle choice).
However, these are focussed mainly around the train stations and a handful of smaller pockets (eg, around the Glen Park Road / McDonalds area in Bayswater). There are very nice parts in all of those suburbs, Croydon included, and there are likely to be people doing things you don't approve of in just about every town.
As far as that particular suburb goes... As Kristine suggested, there are village-like streets in and around Lincoln Road that could be worth looking at. Croydon Hills and Croydon North are also often seen in a better light than the main suburb, but again; execptions to every rule.
Norton Road area is one of those middle band locations; nothing overly special, but not complete scum. There are some very nice walking tracks and parks nearby, and the TAFE and proximity to transport is an obvious plus. Traffic on a weekend is chaotic due to the athletics track, but otherwise nothing too much out of the ordinary to comment on.
The new tollway will also bring Croydon that little bit closer to the city, although I do wonder if some of that growth has already occured in anticipation.
Having said all of that, though; it all comes down to the deal. Does it make sense, and is that particular property likely to help move you towards your goals? $290k sounds like the right ballpark, at least, but beyond that... It really is your call.
Good luck mate
James.