The best time of the year to visit the Gorillas is June July August or Dec Jan Feb, the two drier seasons on the equator.
You can fly in to Entebbe in Uganda or Kigali in Rwanda. Travel by car to Volcanoes national park.
Uganda also has other great national parks with Lions, Chimpanzees etc and trekking in the Rwenzori Mountains.
Tour Companies.
Matoke tours and Bwindi national park and