For most succulents you want to time the watering to correspond to when the soil is drying out. They like to go thoroughly wet (until water comes out the bottom of the pot) and then dry out most or all the way. You will get a good idea of when this happens through experience but you can get some idea by poking your finger into the soil (below the surface, which dries out much faster) or using a chopstick (which will come out a little moist, with soil bits stuck to it if the soil is still wet). There is no advantage in allowing the plants to stay dry for any extended period of time.
Your choice of soil depends on what is available but I would recommend a mix of half organic soil (like potting soil or whatever loose mix you have around) and half rock (like pumice, perlite, lava rock, chicken grit, whatever.... I use pumice).
My typical watering interval for potted succulents in the sun is once a week, given a well draining mix. It depends a lot on the weather (heat, sun, low humidity will cause faster drying) but that's my average interval here where temps are quite mild and the humidity typically runs around 80%.
Your purple plant is an Aeonium. Aeoniums have an annual cycle based on the climate they come from, which usually means active growth from fall through spring and then some degree of dormancy in the summer. So if the rosette shrinks up in coming months, do not be alarmed, that's probably just part of the cycle. You want to try to protect the plant from hot blazing sun in the summer as Aeoniums respond poorly to heat.
It looks like the other plants you have are a Sedum (fat round leaves) and a Kalanchoe (maybe). They should enjoy the same general treatment. When in doubt, provide a lot of light (filtered light is ideal during the summer if it gets hot outside, or maybe morning sun) since they are not shade plants. Again you will get a much better idea of how they respond through experience.
Hopefully this info is helpful. Please let me know if something was not clear.
Kim! 
