Sariska is about 180 km from Gurgaon. It is well connected via highways. We started around 8 in the morning via Sohna-Nuh-Alwar road and reached there around 12:00 noon. Every Saturday and Tuesday National part is open for private vehicles to visit Temple at Pandupole with in National park. At the entrance you have to pay 250 Rs for entry pass. Park is open from 6:00 am to 6:00 pm. Temple is about 10 km from entrance. But you will enjoy surrounding flora with wide species of birds and animals. We went slow and clicked some nice pictures.
Sariska is tropical dry deciduous forest area with species like deers, wild boars, peacocks, nilgai, migratory birds and if you are lucky you can spot hyena, jackal, wild dog, wild cat, leopard or even a tiger :-).
I visited sanctuary in Feb, probably not the best time, there was no greenery in the park. I think if you visit after monsoon between Jul to Sept then you can see more greenery and some water bodies. But that time climate will be hot and humid.
Near sariska there are some option for accommodation. RTDC hotel tiger den is near entrance of park and provides package deals with accommodation, breakfast and dinner. you can book hotel tiger den from RTDC online booking system. A bit far away from park there are more luxurious resorts and hotels which can be booked online in advance.
There are many more attraction in Alwar and near Sariska. You can visit Bhangarh fort (a Haunted palace), siliserh lake etc
If you are traveling from Delhi or Gurgaon then 2 days are sufficient to visit main attractions.
Find listing of attractions at http://www.tripadvisor.in/Attractions-g679018-Activities-Alwar_Rajasthan.html