We recently got back from a safari in Kenya and had a blast. Get a book or printout of the animals you might see so your kids can keep track of what they see. Set aside money for tips for anyone because that is their main source of income. Take a really good DSLR camera and get used to using it before you go. Take a warm hooded coat because it can get surprisingly cold at night and early in the morning.
Are you taking a safari flight? Those planes are often very small and have smaller luggage weight limits. Find out what season you'll be there and whether malaria is actually a concern where you're going. When we went in early and mid-July it was winter in Kenya where we went. We took heavy-duty insect repellent and anti-malarial medicine and never needed either. We saw almost no insects because it was winter and chilly even at the Equator. That may not be your experience though.
Leave some room in your luggage for souvenirs. We got some amazing locally-made artwork and jewelry for very low prices. I was able to get a lot of Christmas shopping done. Shipping stuff home though would have been really expensive. Encourage your kids to keep a journal during the trip and leave spaces in the journal for photos taken during the trip. I have the kids create journal pages that I print out on cardstock and get bound at Kinkos ahead of time. They're a really cheap momento. My older son has at least 10 now.
Here's my luggage tips: use lightweight duffle bags that don't have wheels instead of suitcases. Each family member traveled with a duffle bag and a backpack that they were responsible for (my kids are 12 and 16). We got
one of these in a different color for each family member and they worked great. DS12 already wears adult-size clothing so he needed the same size duffle as everyone else. The bags are great because they have a built-in pocket at either end that is perfect for dirty clothes or shoes. They also come in smaller sizes. I also carried a lightweight purse. I invested in
heavy-duty luggage tags for our backpacks and duffle bags. Each person was assigned a different color so we could easily ID each person's luggage.
Find out which places have laundry services and get your clothes washed when possible so you can carry a lot less clothing. Invest in a convertor plug for each person and make them responsible for their own plug and cables. We found some on
Amazon that have built-in USB outlets. The roads can be very rocky so bring anti-nausea meds for any family member who is prone to motion sickness.
I'm happy to answer any other questions you have.