The New York Times reports on this in English; here are also some Russian-language sources, Kommersant (Ukraine), URA-Inform (Ukraine), and Regions.ru (Russia). According to the Times, the proposal would define the prohibited propaganda as “positive public depiction of gays in public,” and the other articles seem consistent with that; if anyone can point me to the Ukrainian-language text of the proposed law or some reliable Russian translation, I’d love to verify that.
The Times also it is “unclear how much support the bill enjoys among lawmakers,” and that “President Viktor Yanukovych has remained mum about the initiative.” Nonetheless, “the fact that [President Yanukovych's] parliamentary representative Yuri Meroshnichenko supports the bill is an indication that Yanukovych may back it as well.” Kommersant also reports that the authors of the proposed law include representatives of all the factions in Parliament, except the People’s Party (which is a relatively minor party).
Note also that, as the Times reports, “St. Petersburg, Russia’s second-largest city and regarded as one of the country’s most sophisticated, this year passed a law mandating fines of up to $33,000 for promoting homosexuality among minors.”