Hello and welcome to the forum!
Here are some tips that I ca give with regards to visiting Khajuraho:
1. My first recommendation is to postpone your trip only until October or later. Unfortunately, the monsoon season is not a great time to visit the area. Despite the rain, the weather remains humid around Khajuraho. It's also difficult to do some sightseeing especially in the temples when it's raining, as they're in a bit of a distance with each other. The best time to visit Khajuraho is from October to March. The weather during this time is pleasant and cooler. However, make sure that you book hotels well in advance as this is also the peak tourist season.
2. When it comes to transportation, the most convenient and fastest way to reach Khajuraho is via airplane. However, overnight trains are also available from Agra and Jhansi. Unfortunately, trains from Jhansi are unreserved so you cannot book in advance. I cannot recommend buses as the journey can be tiring. Your other option would be hiring a vehicle, which is more comfortable than a bus. If possible, hire a four-wheel drive vehicle as the roads in Madhya Pradesh aren't in such good conditions.
3. On hiring a guide: Guide charges are about Rs. 600 for a group of 4 people for 4 hours. You can find guides just opposite the Western Group of Temples. Otherwise, you can opt to have an "audio tour" which is a walkman guiding you along the temples. You can purchase this at the MP Tourism counter at the Western Group of Temples for just Rs. 50.
4. The temples are open before sunrise and just before sunset. Time your schedule accordingly. It normally takes a whole day to explore all the temples in the area. At night time, there's a light and sound show that you can watch. It is shown at the Western Group of Temples. The fee is at Rs. 100 for Indians and Rs. 400 for tourists.
5. Bring your own flashlight especially if you're going in a cloudy day. This way, you will be able to see the sculptures clearly. The temples rely on natural lighting and some areas might not be as well-lit on a gloomy day.
6. It's customary and respectful to remove your shoes before entering the temples. So make sure that your footwear can be easily removed and worn. Also, make sure that they're comfortable as the journey from one group of temples to another can be long at times.
7. As related to the above suggestion, you can also hire a bike which is at Rs. 30 per hour. It's a great way to explore the temples and experience the rural life at the same time. You can easily ask the locals for directions for your next destination as well.
8. You can find plenty of smaller accommodations in Khajuraho itself. They're quite near to the temples and other attractions. Most of them are clean and will suffice for a comfortable stay. It's a great idea to stay in them so that you can also help the livelihood of the people in the city.
9. The Western Group of Temples have a set fee of Rs. 250 per person (except children). The other groups of temples are free to enter.
10. The Khajuraho Dance Festival happens during the months of February to March, specifically February 25 and March 2. During this time, classical dances are performed with the temples in its background.
11. Lastly, enjoy exploring the temples. Although there are some erotic sculptures, these aren't the main theme of the temples. You'd find temples dedicated to certain deities as well. They are a testament of the Hindu faith and worship during those times. The sculptures depicting day to day activities give us a glimpse of how life was back then. These temples are truly worth visiting and I'm sure you'd find time passing quickly while you're there.
I hope this helps!