Day1-Hire a scooty (Rs800 for one day) or go in government tourism bus.All Mt abbu can be covered in one day. Day2/3/ You can go to Jaiselmar (450Km from Mt abbu) Only one direct train goes to Jaiselmar from Mt abbu(station name is abbu road)
or you can go to Udaipur(170km from mt abbu) I have visited almost all Rajasthan-Jaipur,Bhangarh fort,Azmer,Pushkar,Taragarh fort,Churu,Bikaner,Jaiselmar,Mt abbu. you can ask any query Acc to me,Best is spend one day at Mt abbu then go to Jaiselmar (Desert safari-jeepand camel). Two best things i loved after visiting whole Rajasthan :One is Jaiselmar and 2nd is Bhangarh fort.