It is incredible. It is the closest thing to Indiana Jones that I've experienced (without the Lost Ark, people trying to kill you, etc.) The Mayan ruins are set in the jungle. There are two that you can climb to the top of and many pyramids and temples that you can walk around and in. The view of the jungle is amazing. The guide tells you that this is just a fraction of what is located here, but people are now focusing on some of the other thousands of archeological sites in Guatemala. The guide was very knowledgeable and spoke English well. There was only one other person in our group, so it was easy to ask questions and chat with the guide. There were other guides speaking other languages, so I think that, with a little research, you'd be able to find a guide who speaks your language.
We got a package deal (from a local travel agency) that included a transfer from Antigua to Guatemala City, a flight to Tikal, a transfer to our hotel, a morning tour of Tikal with tour guide, a free afternoon, a night at the Jungle Lodge, food, and passes to Tikal the next day. It was great. One day is not enough because you really only have about half a day in the ruins, which is not enough time to see everything. In the mornings it is pretty crowded with lots of tourists. In the afternoon everything quiets down a lot. You can spend quality time really exploring the things that you breezed by, and the guide gives you suggestions on where to head. It is very worth staying until dusk, when the animals go crazy, but bring a flashlight. It goes from dusk to pitch-dark very quickly. We wandered around in the dark for a while before someone with a flashlight came along, and we walked back to the lodge together. The howler monkeys are incredible, especially considering their size. We also spotted other monkeys and an animal whose tail sticks straight up into the air.
You can also take a bus here, which is much cheaper but very long. With our time constraints, flying was the way to go.