Cant Get Any Power

I HAVE A 2000 TJ AND I WENT OUT FOR LUNCH A MIN AGO BUT MY JEEP WOULDNT START . I TOOK A METER OUT AND CHECKED THE BATTERY AND I HAVE A GOOD BATTERY .. BUT I DONT EVEN GET ANY POWER TO MY DOME LIGHT ... I CHECKED MOST OF THE FUSES AND NONE WERE BLOWN .. THIS HAPPENED THE OTHER DAY TOO AND I WIGGLED THE BATTERY AROUND BUT NOTHING .. THEN I TRIED TO START IT IN NEUTRAL ... NOTHING ... BUT WHEN I PUT IT BACK IN PARK IT STARTED RIGHT UP WITH NO PROBLEM...??? :banghead: .. I TRIED DOING THIS AGAIN BUT I AM STILL GETTING NOTHING ... WHEN I PUT THE KEY IN THE DASH LIGHTS DONT EVEN COME ON .... I DONT KNOW WHERE TO EVEN START WITH THIS I AM NOT REALLY A MECHANIC ... PLEASE HELP ... [email protected]

I would start here http://www.automotiveforums.com/vbulletin/guidelines.html

I'm sorry if that may have come across as rude, but shouting wont help getting help any faster.
Does It start every time you go from P to N and back to P?
Also if you have a test light, you can clip it to a good ground and touch the tops of your fuses and they should light up when the key is turned to on (except the head light/tail light fuses witch will only have power to fuse when said light is on)
Do this to the fuses under the hood and behind the glove box.
Autozone also does free battery testing.
Not to sure where else to look at the moment.