Lizards come in a wide variety of sizes and types. Generally lizards need a safe substrate, a heat source, a basking spot, clean water source and a fresh food source. Some lizards do okay in an open aquarium, but most need an enclosure with a tight fitting lid. Since most lizards are sold as babies, make sure the enclosure is big enough for the lizard after it has grown up. Some lizards like to burrow, other like to hide high on a branch, but all lizards need a great heat source. Lizards are cold blooded and they need to warm themselves up to function properly on a daily basis. A UVB bulb is necessary for all lizards. This bulb simulates the sunlight and is needed for vitamin D production for proper bone development. Some lizards strictly eat meat and others are omnivorous. Insects and worms should be sprayed or dusted with a vitamin supplement and a calcium supplement. Asking an expert or someone with experience with the lizard you are interested in will help determine what you need to get started. Do your research on a particular type of lizard you would like to keep and go from there.