Short answers, pulled from the story.
The word Chetnik first appeared in the mid-18th century to describe members of army and police units. Some scholars trace its roots to the Turkish word çete meaning to plunder and burn down while others argue it derives from the Proto-Slavic četa plus nik translating to member of a company.
Draža Mihailović established the Ravna Gora Movement on the 13th of May 1941 after his group arrived at shepherd huts near Gornji Milanovac. This organization became known as the Ravna Gora Movement when he chose to form a core resistance movement rather than surrender to German forces.
Three most important members of the Chetnik Central National Committee comprised executive committee Dragiša Vasić Stevan Moljević and Mladen Žujović. Dragiša Vasić was designated as Mihailović's deputy and ranking member of the three-man committee alongside Potpukovnik Lieutenant Colonel Dragoslav Pavlović and Major Jezdimir Dangić.
Stevan Moljević wrote a memorandum entitled Homogeneous Serbia advocating creation of Greater Serbia within Greater Yugoslavia including vast majority pre-war Yugoslav territory. The plan included large-scale population transfers evicting non-Serb population borders Greater Serbia though did not suggest numbers and advocated expelling 2,675,000 people including 1,000,000 Croats and 500,000 Germans.
Chetniks signed an agreement with Italian representatives on the 11th of January 1942 to combat Partisan-led resistance. This collaboration continued until Italy capitulated on the 8th of September 1943 when all Chetnik detachments in Italian-controlled parts of Independent State Croatia switched supporting German occupation.