I've been wanting to visit this place for months after seeing it on a nature show. $20 will get you into the park for a day, $30 is an annual pass for sequoia national park and kings canyon park good for 12 months from when you buy it. $80 for USA national parks annual pass. If you enter the sequoia national park it's quite a drive up the one road. It starts off very curvy with lots of switch backs.
Make sure to top off your gas tank before you head up the mountain; it's about 1 hour slow drive before you get to a gas station. The gas prices are slightly inflated but that's expected. There are a few small markets on the drive but you'll be better off packing your own food.
Went Labor Day weekend and the weather was hot/warm at the base of the mountain. As you climb in altitude you can expect it cool down significantly, even during the hottest hours of the day. When you finally get there, spend about a half hour to an hour walking on the paved walkway through the grove. It was all breath taking. I'm sure I stopped to take pictures with every tree and huge rock in the grove. Definitely looking forward to visiting again.
Best part of the trip are all the convenient pull off parking areas on the shoulders along the most scenic spots on the road.