November babies plus 1

I have had mac for 15+ years now and so for the last 4 1/2 years I have been following a yellow e trex arrow around I am excited that I might finally get a Legend HCX as a late mother's day present and be able to plug it into my mac. Are the maps that come on it some what adequate? Where do you go to get free maps? Thank for any help, even though I have been caching for a while, I am completely GPS naive.