In which section of the site the author mention guides in St.Petersburg, Russia?
It's probably not on this website. You can buy one of Rick's books that covers St. Petersburg (Northern European Cruise Ports or Snapshot: St. Petersburg, Helsinki & Tallinn), or you can ask a Rick Steves staff member to "chime in."
Our Northern European Cruise Ports book as well as the Snapshot: St. Petersburg list tour guides. Here are some of those recs to get you started.
Tours in St. Petersburg
Walking Tours--Peterswalk has been doing excellent, English-language walking tours of the city since 1996. Their original, four-hour tour is a great way to get your bearings here (650 R/person, mobile +7-921-943-1229, www.peterswalk.com, firstname.lastname@example.org). This tour begins every day in summer (April-Oct) at 10:30 at Hostel Life, at Nevsky Prospekt 47 (near the Fontanka River--enter around the corner at Vladimirsky Prospekt 1 by ringing the bell and going up to the fourth floor; tour may run sporadically off-season--check website).
You can also hire a private guide through Peterswalk (1,200 R/hour for up to 8 people, 4-hour minimum; this price assumes you already have visas, but for an extra fee they can also arrange a visa-free private excursion--email the owner Peter to arrange details).
Bike Tours--Peterswalk (listed earlier) offers 3.5-hour weekend and late-night bike tours (mid-May-Sept Sat-Sun at 11:00, also mid-May-Aug Tue and Thu at 22:30, 1,200 R/person, starts at SkatProkat bike shop at Goncharnaya Ulitsa 7, near Moskovsky train station and Ploschad Vosstaniya).
Boat Tours--St. Petersburg is a delight to see from the water. Low-slung canal boats ply their way through the city, offering a handy orientation to major landmarks. After curling through narrow, urban waterways, your boat pops out onto the wide Neva River, offering a grand panorama of the Hermitage, Admiralty, Peter and Paul Fortress, and beyond. Various companies offer essentially the same one-hour, 500-R cruise, advertising at touristy points near canals; most cater to Russian tourists and have zero English information. (Before booking, specifically ask whether there’s any English commentary.) Better yet, hold out for the one-hour cruise from Peterswalk, whose guides not only speak English, but cater the commentary to passengers’ interests. While it costs a bit more, it’s worth it (600 R/person, 3-4/day in peak season--but check website for specifics as schedule and offerings are subject to change, departs from Fontanka 53--along the Fontanka River a long block south of Nevsky Prospekt; same contact details as for walking tours, earlier).
Bus Tours--CityTour runs red, double-decker, hop-on, hop-off buses that make a circuit of major sights in the center, with recorded commentary. The full circle takes two hours, but the frequency is sparse (once per hour)--potentially leaving you with more time than you want at a particular stop. The first buses start around 9:00 and the last one finishes its route just before 21:00. A ticket good for the whole day costs 500 R; buy it on the bus (tel. 718-4769, mobile tel. +7-961-800-0755, www.citytourspb.ru).