Ivangorod — the Russian half of a city split in two at the fall of the USSR, across the river is Narva and two big medieval castles stare each other down from each city across the Narva River, the new border of Russia and Estonia
Lodeynoye Polye — home to a pretty cathedral and the Alexander Svirsky Monastery
Priozersk — a popular dacha town with a big medieval Karelian castle
Staraya Ladoga — an incredible gem of a sleepy village, this is the first capital of Russia, founded in the eighth century, which was for its first 200 years one of the most important ports in Eastern Europe; boasts some very old churches with twelfth century frescoes painted by Russian Master Andrei Rublev and Russia's first kremlin, built by the first Russian Tsar, the Rus Viking Rurik
Leningrad Oblast is most often visited by travelers staying in Saint Petersburg, either on a day trip or overnight to places of interest. If you are interested in Russian history or Orthodox art, you should put Staraya Ladoga at the top of your destination list, but be aware that it is difficult to get to on your own so get a tour. If castles are more your thing, Vyborg, Shlisselburg, and Ivangorod are excellent destinations, but in the case of the latter, be sure to get all your paperwork in order because the Estonian side of the city is more interesting and accommodating. Finally, if Saint Petersburg and its suburbs have not tired you out of seeing palaces, Gatchina's palace is quite impressive.
As a general rule, the closer you are to either a major tourist site or to Saint Petersburg, the more likely you will find people who speak English or other European languages, like German, Finnish, or French. Still, some knowledge of Russian or a qualified guide will almost certainly elevate your experience here.
In general, the most efficient and cheapest mode of transport is to take the electric rail elektrichka (электричка, eh-lehk-TREECH-ka) services from Saint Petersburg's main rail terminals. Tickets are very cheap and the elektrichka will take you to all but the smallest destinations in the region (Staraya Ladoga).
The whole of Northwestern Russia and major cities across all Russia await from the rail stations and airports of Saint Petersburg. The region is also a convenient last stop in Russia for travelers heading on to the Baltic states, Finland, or Belarus.