First of all, let me start by saying I hate mining and I do not recommend it to anyone. The bots have driven prices into the ground, making mining very unprofitable.
However, if you are new to mining and want to give it a shot. I will give you some advice on how to make the most of it and not get killed by a PVPer like me that will flip your can and blow up your mining barge just for laughs.
First of all, if you can avoid Jet Can mining by using a Orca or Hulk that has Cargo Rigs, I suggest you do it that way.
Second of all, DO NOT MINE ICE! That's what 90% of the botters mine, it's long boring and a waste of time.
Now that we have that out of the way let's talk about what "Jet Can Mining" is. Basically, when you jettison something from your cargo, it creates a cargo can that has 27,000m3 space. This makes for a great place to put your ore while mining so you don't have to run to station every 2 minutes. This is called a Jet Can.
When you Jet Can mine, you mine until your mining ship's cargo is full, jet the ore into a can, then repeat until your Jet can is full. Once your can is full, you either go get your hauler and haul it to station or you start a new can.
However, remember that your cans only last about 1.5 hours from the time you jet them. I'm probably a little off on that time, but it's pretty close. So make sure you get your ore before the can disappears.
At this point maybe you're thinking... "Hey, I'll just name my can with the time so I know when it was made!"
Not so quick... Can Flippers (that's what they call people who hunt poor defenseless miners for fun) actively search for cans named this way. I can speak from LOTS of experience that a can with the time on it make life so much easier for a Can Flipper.
So DON'T name your cans. Leave them looking the same as they would look if they were cans left over from salvaging or something. Can Flippers will still find you, just not quite so often or easily.
But what if a can flipper does find you and flips your can? Should you go get your new Harbinger and teach him a lesson?
NO... Realize that can flippers do this stuff all the time and they are not just expecting you to do that, but they are hoping you do, so that they can get a bigger kill.
"But they are in a little T1 Frigate. That can't hurt my Harbinger!"
Maybe, maybe not. But even if that little frigate can't. The moment you "aggro" you will be giving them 15 minutes to respond and there's nothing stopping him from going to the station and getting a bigger ship. Again, realize you are playing a game with someone who plays it over and over everyday.
You don't go from never playing Basketball to walking on the court in a NBA game and expect to not do horribly.
There are some games that can only be won by not playing them.
Should your can get flipped there is one thing you can do that will hurt the flipper more than anything else, even if you were to destroy his ship (he doesn't care if he loses his t1 frig).
That one Super Response that will piss can flippers off to no end is to simply DOCK! then sit in station until the flipper has left the system (local chat).
Should you want your ore back after he left, do not go try to take it. He could have a alt cloaked watching and waiting for you to take it.
The best way to get the ore back is to have a third party, (your alt or a friend) flip the can using a shuttle or rookie ship, then dock for 15 minutes until their aggro timer expires. Once they have flipped the can you can pick it up with zero risk because you are stealing from your friend or alt and not the can flipper.
Stick to these guidelines and you will avoid dying to can flippers...
But you still might die of boredom or potentially to a Ganker.