There are a number of great tools available (or coming very soon).
1]
HackIngress will be coming online soon enough after a short delayed time schedule.
2]
Ingress Portal Calc keeps track of all of the AP amounts, information about leveling, burster levels/calculator, portal configuration, etc.
3]
Ingress Portal Timer watches your portals and times their cooldown for the next round of hacking!
4]
Filed Trip from the creators of Ingress (Google's Niantic Labs) is useful for finding nearby portals.
5]
Ingress AOKP/CM9/CM10.1 is a fun Ingress-style theme for your device.
For those just starting out though, nothing really beats playing the tutorials, replaying the tutorials and getting out into the game (world?) and messing around.