Hey, lived in Ilsan for 18 months and you have chosen one of the best cities in Korea for all round livability and convenience.
It's a residential city for middle class famillies and I always found native Ilsanites very friendly, laid back and accustomed to foriegners.
Lake park is gorgeous (well for Korea and the fact it's an artifitial lake) and a good half day out, jeongbalsan is a nice easy hike, the larger bhukansan is nearby also and there are loads of free outdoors gyms everywhere.
For entertainment La festa and Western Dome areas have everything you need; several megaplex cinamas, foriegn food restaurants, coffee shops and there are several foriegner bars too, but i forget the names and they've probably changed since I was there 3.5 yrs ago.
I found the general non region specific Korean food to be of above average quality in Ilsan too, better than in Seoul in fact.
Also, Seoul is only a 45 min bus ride away and the busses run until around 1am both ways.
Plenty of foriegners living there too.
I always found the light there to be very good too, really, narey (is that a word, I just woke up) an overcast day and the most jubillant springtimes I ever experienced.
A first timer to Korea really couldn't have chosen many better locations imo and ime.