I just spent 5 days camped at Flagstaff Lake in Maine, if you google it you will find lots of information. I also have the book "Quiet Waters, Maine" which has a somewhat dated write up about the lake also.
After some searching I was able to find the old logging road called Falgstaff Road and drove in past numerous downed trees to the lake.
The lake was low for springtime, the ice had just gone out and the low water levels left many beautiful beach's.
I brought my small downsized 8x10 wall tent, now more like a 7x6 with a lower ridge and a lightweight dowel interior frame with a small 12x12x12 wood stove. The temps went down to 30 F at night, but up to the mid 60's in the day. It was nice to have the comfort of the stove early mornings and late evenings.

Across the lake is a mountain range which made the whole setting really nice.

Mornings where pretty layed back, lots of coffee, some health food for breakfast and more coffee.

Camping on a beach has it's downfalls, what with the sand and all, but my tent was up on some low grass and I had the best of both worlds. I stayed at this spot for the 5 days, paddling down the lake for day trips.

One morning I had some company, a small plane flying low over the lake

I spent most days exploring the beach's, looking for tracks. I saw moose, beaver, coyote, fox, snapping turtle and lots of bird tracks in the sand.

Exploring the shoreline in my canoe was also fun.

Some spots still had snow

I was lucky to have such nice weather, I think I was a week or so early for the brook trout and salmon, but the camping and paddling was perfect.
Some Maine canoeing information-
Appalachian Mountain Club River Guide, Maine
Appalachian Mountain Club, Quiet Water, Maine
Both of these books are excellent trip planners, there are both rivers and lakes where you can really build a nice trip, sometimes without any fees and both books help you sort things out and plan.
If you have a lake in mind already and need a free fire permit for campfires, phone # for Maine Forest Service, 207 827 1800 to be given a free fire permit number, very easy.