Hi JemaPee,
We live in that area, specifically the small estate the other side of Barnsley road, near the graveyard.
As mentioned, Portobello is a bit dodgy, but anywhere south of Manygates college is quite nice (going up the hill toward Sandal castle). The houses around sandal castle are good, and there's a decent volume of interesting things going on at Manygates.
Agbrigg is reasonably friendly (despite the appearances), however, in the evening it does tend to have some idiots haring around in cars driving too fast.
Walton and the estates south of Sandal & Agbrigg train station are nice too, and Walton has a cracking pub.
Stay away from Bell Vue though, which is the estate around Doncaster road, unless you have a burning desire to have your car, teeth and children stolen.
I've lived around here for 4 years and I've never witnessed any crime, however a couple of people on our street have had various bits of metal nicked off their property. Not sure why wakefield has such a propensity for nicking bits of metal but it is kinda famous for it. Just don't buy a house that's made out of copper.
Tom
(yes I'm not a woman - my wife hates the internet)