I grew up near Lyme CT where the disease was first recognized and were the ticks are quite thick. I survived 18 years in the region without contracting lyme disease. The most valuable thing you can do is to check yourself over very carefully when you get out of the woods/marsh then shower as soon as you get home. I've lived in central VT for the last 9 years and ticks are just now creeping into the hills of my home. I used frontline for a while on my two dogs but continued to pickup ticks in the Champlain Valley, eventually leading to a positive lyme test for my spaniel.
I tried using the Scalbador collar which contains premtherine (sp?). My lab was OK with it, but my spaniel had a terrible reaction to the collar. My vet later acknowledged that 3 dogs of the 20 he had sold collars to had serious reactions to Scalbador. I now use a different tick collar (Advantick I think?) and will be applying frontline next week as I head to the fields more often for the start of goose season. My hope is that the double up of protection will prevent a re-infection of lyme on my spaniel.