We just got back from Oceania's two-week Scandanavian cruise - see the postings at http://cruise-forums.com/forums/read...&i=1506&t=1506
for some brief pointers. Tom Ogg also posted his trip diary of an identical trip he took aboard the Renaissance R7, which we used as our template: http://www.cruisereviews.com/ren/r-7-2.htm
. Oddly, not much changed in the two years between his cruise and ours!
We augmented Frommers with DK Insight's Guide to Scandanavia, which had lots of useful walking maps and photos. We also bought DK's separate St. Petersburg guide, which was useful as an indepth resource (Oceania spent 2 days there in 2003, and will be spending 3 days there in 2004). One person had Rick Steves' guide, but it was more for the backpacking type of tourist - too many hotel and restaurant recommendations and out-of-the-way attractions to fit into a one-day port call.
You can use the books to tour St Pete's on your own, (after paying $100 for a visa) but if you don't speak or read Russian, I'd recommend hiring a guide. The city hasn't prepared for the influx of English-speakers, and even those who claim to "speak English" do a pretty poor job of it. Red October was our guide service and we had no problems getting around.
By the way, Amazon.com is offering the 2003 guidebooks for 30% off - buy them now, before the 2004 editions come out!
E-mail me if you have any specific questions.