Very nice area, especially if you have kids. Johnstown primary schools (boys & girls) are at the top end, beside the church. Downside is that its actually on, as opposed to close to, a few bus routes (7 & 45a come to mind) so it's a bit difficult in terms of privacy as passengers can see in upstairs as well as downstairs! And a bit worrisome if your kids are very young, they can't go out to play safely in the same way as in some of the Watson or Auburn roads close by which are much quieter.
Tesco in Ballybrack down the road in the opposite direction from the church, small shopping centre also has Xtravision, newsagent, chemist, off licence, greengrocers, hairdressers & Chinese takeaway.
Short walk to Killiney shopping centre which is dreadful for parking so it's good to be able to walk to it! I was in the Graduate pub a year or so ago and the food was pretty good. I've heard the food in the Rochestown Lodge Hotel (a bit further along Rochestown Ave.) is good too, but on a couple of visits to the bar I found the atmosphere there a bit soulless. If you're feeling energetic, Killiney Castle Hotel is walking distance (and downhill on the way back). Both hotels have gyms & swimming pools, membership required.
Probably about 20 minutes walk to the Cabinteely junction of the N11 where the 145 goes into town, under 5 mins by car to get there. If you're going to the M50 probably best to access it via Cherrywood, again about 5 mins (outside rush hours though!).
Secondary schools in reasonable supply, Cabinteely Community School (mixed) on Johnstown Road, Clonkeen College (boys) on Clonkeen Road (can be accessed by bike or on foot via Cabinteely Green & Monaloe), Cluny (fee-paying girls) off Avondale Road.
As addob says, Cabinteely football park is a popular spot, Seapoint rugby club is also there. If golf is your thing, Killiney Golf Club is only yards away from Churchview Road.
I'm pretty familiar with the area so if you've any other questions ask away.