New to gps and only slightly better at WinXP.Have downloaded basecamp , mapsource and garmin training center .I will be using 450 for driving 4 wheel drive truck in National forests looking for trails and geocaching.On here I found a great TOPO MAP and an OVERLAY for trails, these appear to be exactly what I need/want.Can I use these in conjunction with each other or do I need to get the garmin topo and use the overlay from here? Should I use an SD card for this?
Most overlay mapsets with work with most 'basemaps'.
Either, depends on how much free memory you have on the unit. Either way BACKUP what came on the unit incase it gets accidentaly deleted.
If you place a corrupted file on your unit, it can cause it to freeze during the boot process and not respond when plugging in a USB cable. This prevents you from accessing the Oregon to delete the problem file and your unit is basically a brick. There are a couple techniques that will usually help get you out of this, but it's kind of a panic the first time it happens to you. With a Nuvi automotive GPS, a corrupt map file can literally kill the unit - freezes during boot and nothing helps.
So, if you really want to play it safe, always put new maps on a memory card until you verify that they work properly. I never used to do this myself until I had a couple problems with beta versions of my own maps in fact.
THAT IS VERY GOOD ADVICE! I also saw on here a suggestion to back it up to CD-now i will need to find out how to do both of those