You can find a range of hotels depending on how much money you want to spend. There are a lot of mini-hotels which I can recomend if you don't want to spend a lot of money for the hotel.
Please go to the site
www.saint-petersburg-hotels.com
if you want to find a description of hotels and select whichever you like. There you will find web sites of hotels and you may reserve rooms there or on this site of company.
If you want you can chose my help and I will make reservations for you.