Hi Larry, as Paul says, Red October have an excellent reputation for their tours, but check out any special Visa requirements, again Red October will help if needed.
We've cruises the Baltics & Northern Europe several times (we live in Southampton, GB) and taken several tours with Princess. The are generally well organised & reasonably priced - however with the GBP's recent collapse, you will appreciate the prices more now that we will ;-)
Were there any ports or tours in particular that you wanted comments on?
Alan & Katrina
Last: Oceania Nautica Aug 2016
Next: Cruise Maritime Magellan Nov 2016
Then: P&O Oceana December 2016
Golden, Grand(2), Caribbean, Royal, Sea(4+1 aborted)
Adonia(4+2), Arcadia, Artemis(2), Aurora(5), Azura(2), Britannia, Oceana(3), Oriana(12), Ventura(2), Victoria(5)
QM2(2), QE2(9), QV(7), QE, Caronia(2),
Oceania Nautica, Minerva, Minerva II, Fred.Olsen(8), NCL Jade, =X= Eclipse, HAL Ryndam, Aza.Journey