Naivasha is a city in Kenya.
A matutu from Nairobi to Naivasha takes around 2-3 hours and costs between 3-400 Kenyan schillings (3-4USD). It's worthwhile to find an 11-seater, rather than the more crowded 14-seaters, to make your journey more comfortable. A matutu from Nakuru to Naivasha takes about 1.5 hour and cost about $3 as well.
Get a bike. It's the best way to see the sights near Lake Naivasha.
To go into town center, hitch a ride or take a matutu for less than $.50
Rent a bike for $5 - $8 per day and bike to the Flamingo Lake (7km each way).
Visit Hell's Gate National Park - Entry $26 USD with additional $2 fee for bicycles. Entry must be paid by card, as cash is not accepted. There is a lot of information online advising against cycling through the park, but this is an extremely enjoyable experience. If you have a basic level of fitness and it hasn't been raining, it is the best way to see the park. Make sure to bring a hat and sunscreen if the weather is hot.
At Hell's Gate you can pay a guide to take you down into the gorge - short or long walks are available. Consider renting bicycles from the locals at the entrance, rather than from the park itself. Ask for Daniel or David - they are reliable people.
Climb Mount Longonot - A quick ascent to the top (around one hour), and a beautiful hike around the rim. Entry must be paid with card. Bring sun protection as shade is limited.
Visit Crescent Island
Take a boat ride on Lake Naivasha. You will most likely encounter Hippos
Contact Timmy if you want to organize trips around the area or Masai Mara. He hangs out at Fisherman's camp - +254 723 904129
Contact James if you visit Hell's gate National Park, he's a bike guide there - +254 713 250356
You can get delicious local food from any of the restaurants (sometimes called hotels) in Naivasha town. Prices are very reasonable, and you can ask the staff if unsure what something is. Ebenezer Cafe is a partiularly good choice. Jolly's Cafe has been known to rip off tourists.
If you intend to stay at Fisherman's Camp, bring snacks. The food there is expensive and Westernised.
Most of the campsites have bars. Fisherman's camp has an annual music festival in February.