You can also try Medvezhyi Ugol ( ) 7 (0852) 303585, it a smaller private hotel. But I am not sure about English.
Anyway, it may be fun to talk to them on the phone.
These Kotorosl' and Yubileinaya are the best, you have to understand that Yaroslavl is quite a provincial town, although very beautiful, particularly in summer.
Check here www.yars.free.net/English/Region/reg.en.html
there is a lot of infromation