Battery operated water timer are the easiest and the most cost effective irrigation solutions for your garden i would say.
compare to solonoid valve and controller system , battery operated water timer required only alkaline battery to operate and this make the installations process easier.
If you have a slightly bigger garden or lawn area , you can make a zonning system for your garden irrigation. Normally i will use up to 3-4 water timer for a garden of 2000sqf for pop up sprinkler installation. Each water timer will controller up to 3 sprinkler or a single way drip irrigation.
at http://www.sprinklerhouz.com/ you can find some battery operated water timer that suits your need. there is regular water timer and there is solar charger and rainstop funtion water timer.