As a rule of thumb the southern end is much nicer than the northern side.
To the south is Worsley and Boothstown which are very nice and the home to some Premiership footballers.
The north is Little Hulton which is home to several of the Happy Mondays! Say no more!
The town centre is pretty grotty, dominanted by a large tesco and is to the Little Hulton end of town.
Saying that though it is is handy for the motorway and has a good bus and train service. The main road through Walkden is very busy but like i say to the south its is very leafy and rather nice.
Not an unpleasant place but not particularly desirable and like i say up towards Little Hulton it is a bit rough (well quite rough actually)