The Cottagers announced the move on their official website, adding that they have the option to sign the 29-year-old for a further two years if they want to.
A 29-cap international for his country, Manolev started out with Pirin 1922 before a move to Litex Lovech, for whom he scored the winning goal in the 2008 Bulgarian National Cup final.
Twenty-six-year-old Emanuelson has also agreed to move to Craven Cottage until the end of the season.
Jol has managed Emanuelson in the past, with the pair working together at Ajax, and the Fulham manager said: "It's not easy to get players from AC Milan on a permanent basis.
"I coached him at Ajax. He is a skilful player, very agile. He is very mobile, quick. He can play left midfield, wide, play number 10 so I feel we need fresh legs."
It had looked as though Pajtim Kasami would be on his way out of Fulham, but it appears that a technology problem could have got in the way of a move to Pescara.
The Switzerland Under-21 international tweeted "why is everything going against me" with his agent later being reported as telling Sky Italia that the necessary paperwork may not have arrived on time.
"It's ridiculous that the internet connection has not been working correctly," Mino Raiola said. "We completed all the documents before the deadline but we don't know if they arrived in time."