It's actually what newbies are pushed to start from when they join goons - and they get handed a free noctis. space socialism
They salvage behind anom ratters in some of the best space in the game, and you can do it as a few days old character.
Salvaging anoms is a lot more realistic than telling a newbie to get involved in C6 capital escalations within wormholes.
it can be anything, the only thing that limits new player is time, friends and intelligence, yeah lvl 4s pay enough, belt ratting and anoms pay good too. WHs and Incursions are an ISK faucet, the problem is that they are top skill content. it means a several days noob cannot do them properly solo WHs can be done to a degree, solo incursions are impossible anyways. i dont know how much pay the WHs from C1 to C4 BTW, i've only used WHs for short travelling. planning a long term goal of living in one using 3 chars (an scout/cyno, a fighter/miner and a industrialist/logistic). if the new depots and personal deployables come handy the next expansions i'll see if i can accelerate things with only one char.
again, my best recommendation for a noob who wants to make money at the start of the game and in the case it has the account means to keep doing it and improving is security missions, you can get quite a good income at the start, and keep scalating, if you save your LPs you can get good sales with some faction items, i've reached L4s in a month, and they're very rewarding, the challenge is learning to do them and get good skills for your ship. training for security missions also gives you skills that could be used for PVP and other combat related activities.
mining can be profitable when done right (no AFK), be it ice, ore or gas (looks like WH gas types are really rewarding). and new you can get a mining barge in less than a month, the problem is that CCP hasnt invented a way to make it fun, keeping drones killing rats while you're putting attention to your laser cycles is annoying when you're more than 8 hours of play. only to do like 60 million isk a day.
exploration is another easy income, the problem is that with the last expansion it became so easy to do that basically the price of the exploration loot and salvage has fallen to the ground, only some faction stuff has the good price (faction towers for example, but i think they'll keep going down on price).
planet interaction is another good isk income, not so in empire space due to taxation, i hope Rubicon will allow to fix that to a good degree, i wouldnt matter at least paying half of the current tax for it. its a passive income which bases around the sec status, so try to find a null sec alliance that has a custom office or use one in low sec, in high sec you require to control several planets, but you can make some millions at the end of the month.
from all those i gain my accounts income via mining/PI and security missions, quite a feat for me....i recomend doing ratting in null but living in an alliance is very annoying sometimes, also, you never know when the next territorial change is gonna be.....