Icehouse isn't a cheap day out if you're taking a few kids - the concession price is almost the same as an adult, but if your kids have stamina you can stay as long as you like, which makes it better value.
If you're not into whatever horrible autotuned music is on high rotation on commercial FM stations you might want to bring along your own music player or some ear plugs. On school holidays they ramp it up with a DJ playing the same obnoxious crap, but louder and with daft banter in between songs. The hockey rink is better when it's available because they don't have the music playing there.
The best thing I've found is that It's really cheap to upgrade to the premium skates ($2) and it makes the experience much more enjoyable. They skate better, even when you're a beginner like me, and they're more comfortable, or more correctly, less uncomfortable, especially after an hour or two.
It's worth going later in the day on school holidays. Early in the day the rink tends to be packed with lots of little kids falling over everywhere. If you get there around 3pm the crowds start to thin, and at 5pm the DJ goes home (did I tell you the music was rubbish?) and it all gets a lot more pleasant: fewer people, quieter, and the ice doesn't get messed up so fast. Since they're open till 10pm you still have a lot of skating time.
If you are taking kids and don't want them eating junk food, or indeed if you don't feel like eating horrible greasy crap yourself, bring a packed lunch.
Wear clothes that won't soak up water and get uncomfortable when you end up on your arse. It's always a bit cold on the ice (well, duh) but you warm up if you're skating, so layers are a must. If you're a beginner, gloves are a good idea. The free lessons they do on school holidays are worth it, just for the lesson on what to do when you fall over.
TL;DR: a bit on the expensive side, but good value if you want to stay for a while. Crap music. Upgrade your skates. read more