I have the same boat, 2005 model. First off, the batteries are arranged from left to right as the first two being port starting the second two being starboard starting / house battery. So when you are looking at the batteries from LEFT to RIGHT the switches will be: first battery, left switch set to 1, second battery, left switch set to two, third battery, right switch set to one, fourth battery, right switch set to two. Battery charger must be optional as I do not have one on my boat but am considering adding one soon. To charge the low battery, set all battery switches to off, and simply connect your charger to the low battery.
The nav lamp should have a twist off cover. I believe the lens case simply screws off and will expose your bulb.
If your boat does have a promariner charger it would likely be mounted above the batteries out of view. You can either remove the plate that holds the two switches and look back there (be careful to not touch the battery leads and only remove the screws on the outside rim of the plate, not the ones in the middle as these hold the switches in place) or you could maybe use a mirror to look above the batteries at the space that is up there. You are looking for something along these lines
http://promariner.com/productFeature...oductNum=51015
Hope this helps, enjoy the new ride, they are a very solid boat!