The best way to go is by car (and the truth is the only one I know) is not far from Valencia, almost all the way it's by highway or similar. If I remember correctly shortly after passing Segorbe, there are signs indicating how to get , it's pretty close to the motorway Mudejar. (I add the google maps link).
Here I put the program taken out of the website of the City Council of Jérica:
Friday June 29
24:00 Performance at the Meson
1:00 Discomóvil in Multipurpose Room
Saturday June 30
11:00 Turning General Bell announcing the start of the Medieval Market
11:30 Inaugural Parade XVI Handicrafts and Tourism Fair with Medieval Market Ms Teresa Gil de Vidaurre.
12:00 Parade with musicians. All day we have the animation of a Fool.
12:30 dress knight and paladins duel (Town Hall Square)
13:15 Exhibition of Birds of Prey. Parade with musicians.
14:30 Pot's Distribution traditional dresses all the time in the Meson de la Plaza del Maestro Puchades.
18:00 Parade with musicians.
18:30 Museum of Weapons (in The Meson)
19:00 Animation in charge of the Fool by the market.
19:30 fencing class for children in the Plaza del Ayuntamiento.
20:00 Parade with musicians.
20:15 Exhibition of Birds of Prey.
21:30 Parade end.
24:00 Verbena in Freedom Square.
Sunday July 1
11:00 Market Reopening. Animation all day by the Fool.
12:00 Parade with musicians.
12:30 Dance and brawl in the Plaza del Ayuntamiento.
13:00 Parade by the drum group "Tambórica"
13:15 Exhibition of Birds of Prey.
18:30 Parade by the drum group "Tambórica"
19:00 Playground.
20:00 Parade finale
Have fun!
poster taken from the website of Council of Jerica