Having done a few I would suggest you start off with short ones.  The first lake I bushwhacked into I only took my fishing pole and did some shore fishing.  You will find some have portages that are just not marked on any map. Note the suns location before leaving the shore.  It will help keep you closer to your intended heading.  Check your compass frequently for the same reason.  You cant keep on a straight line because you will be going around obstacles that will get you off course and that is why you need to check your heading.  Another way to navigate is to follow a creek or valley to your new found lake. 
I have found that the fishing can be much different on a smaller lake.  About 15 years ago my brothers and I were base camping on Saganagons in early June.  We had been fishing fairly hard for 2 days and hardly had any fish.  I took the gang into Moose Bay Lake much to the grumbles of everyone.  They came along just because there wasn’t any fish bighting they might as well do some exploring.  Well all the kids and I got to see a moose and every one caught Northern and bass.  There is no marked portage but if you look around you will find where many people have made their way in and out.  There is the remains of a trappers cabin some where on that East facing hill that flanks the entrance to Moose Bay.