hi, congratulations! watering is the number one, most important gardening practice ( ok, along with giving enough sunlight and good drainage) when a plant goes wrong it's mostly one of these reason before any pest and disease.

most people tend to water too much. and getting into a good habit of it either a container or the ground will save you alot of trouble. ( plant dying and all that stuff)
my general rule of thumb is not to water until the first about two inch of the soil feels pretty dry, when you stick your finger in it. it could be a little damp but more on the dry side. that's when i water. so there's no way telling how often because it'll depends on how big the size of containter is or what it's made out of. bigger would be the less often , plastic less often , terra cotta more often ( porous) whiski barrel somewhat similar but probably not that often since it's big, glazed pot somewhere between the plastic and terracotta..... so on.
there's an exception to this. right after you plant, if it's newly potted and you broke the rootball. i'll keep them pretty well watered for oh, i don't know for a couple of days. depending on how hot it is out , hotter , sunnier the longer. up till about a week or week and a half, maybe( in the middle of summer) so they can have time to grow new roots and get over the shock. that's just because the roots are broken so you'll see the plants wilt faster in that period. but be careful, this is a fine line probably only comes with more experience to have a feel for it. but plants wilt from too much water, too. so somewhere along the line you'll go through trial and error to tell how much is too much.

you are absolutly right it'll also depends on what kind of plants you grow. some plants likes to be on the dry side some on the more wetter. but exception of a few, most plants basically hates wet feet. most likes them evenly moist. which means you don't want to water often but when you do water deep. meaning you want the water to come out of the hole at the bottom . this applies to both container and ground by the way.

one thing you should keep in mind in container is that the potting mix is completly different from regular garden soil, it's mainly made with peat and barks and they are very difficult to rewet if the soil dries out too much. so sometimes you'll see if you water a dried pot, the water come out at the bottom too fast. this is no good, the water is just falling and the pot is still very light. if you stick a finger in it it's wet at the surface but bone dry in side. it's somewhat a pain you have to go through to rewet the soil. if it's small you can take it to the sink or soak it in a big bucket for a while until it reabsorb. if it's too big you might just have to keep water next two three days. in the ground, you don't have to worry about this.

mulching the ground or container can help, more so on the ground. so if you mulch it'll really help to conserve water. alot of times you only have to water during the very dry spell.

it's will be pretty hard keep away yourself from watering. sometimes i even have to fight it off. but always remember, it's always better to be on the dry side than wet. this might help you restrain when you just wanna water for really no reason. this happens to everyone since everyone overwaters.

i hope this helped. good luck.

Good info suzi7!

I would like to add a little tip I learned when confronted with bone dry soil in a large container. I either use warm water or I use my fingers/cultivator to break up the soil surface where the soil meets the pot. This eliminates the "void" that was created when the soil pulled away from the pot as it dried. If not done, the water will just rush through the void, avoiding the rootball (as you mentioned).