There is easy to access free wifi throughout the airport - high speed and unlimited.
If you're lucky enough to be granted access to any of the Emirates lounges - there is one in each of the terminals, try get to A or B. A is the newest and has the most capacity but B has a hidden gem in the complimentary Costa located in the lounge with abroad range of beverages and a decent range of snacks. The Emirates lounge also offers full Asian, western, middle eastern cuisine as well as a health bar.
Traveling between terminals can take a little while - budget on 20 minutes to be safe. You cannot walk between all terminals and need to either be transported in the internal train or on a bus.
If you have a long layover, consider using the Dubai airport hotels - located inside the terminals - well priced and well serviced.
In terminal A, there are also travel pods and cabins, the pods large enough to hold you and your carry on and allow you to lie down for a little while. The cabins are larger and can accommodate a small family. Take note though - there are in the main thoroughfare of the airport and outside noise does bleed in.
Another lounge option is the Marhaba lounges - accessible either by paying AED175 pp at time of writing, or though a credit card affiliation.
Outside of the lounges, each terminal has the standard duty free that you'd expect, a host of Starbucks and Costa Coffee shops, specialty restaurants ranging from Paul to Giraffe - again the variety differs from terminal to terminal, with C being the least exciting.
For kids, Terminal B, both Emirates lounge and the terminal itself, have a kids play area. Worth a visit if your kids have pent up energy they need to burn. You'll thank yourself later when you're back on the airplane.
Let me know if you have any specific questions and I'll be sure to answer them