Leano on the east side is the most popular entry (you still never see anyone, since it is so remote).  The logging road (50 miles to Leano) has been bad in the past.  It is VERY important to call the park office if your going in on the east side, and find out what that road looks like.

It is not like the BWCA/ Quetico, and your not likely to see anyone, especially on the western side, and during the spring and fall.  Leave a good trip plan with your best friend, before you leave.  They get about 700 visitors a year, and its a big park.  The BWCA gets that many at a single entry point, by the end of June.

The Gammon and Bloodvein rivers/ interconnecting lakes all have walleye.  Pike are throughout.  Lake trout in all the big lakes.  No smallies in WCPP.  Muskie only in Irregular lake in the SW corner.   The office has a nice sheet with known species by lake.