History - i wanted to be a trader...
Last time i spoke about manufacturing, anybody can do it, but not anybody can make profit out of it. Same with trading and anything else in EVE. I did like a month or two of trading to be able to comeback on my main (inspired to trade by croda).
I've started like him, with a 8mil capital from career missions (sold all the stuff i got) and searched for a good margin margin items that i could buy in Jita and sell in Dodixie, i bought mostly blueprints and ammo and i hauled with a strip fitted Catalyst.
I could make somewhere between 10% and 50% profit for every item but ammo and if i would been less lazy i could make enough to plex two accounts per month. Sadly some items were so low in trafic so most of my ISK was stuck for more than a few days (this happened with some blueprints, t3 subsystems and some rigs).
Present - you want to be a trader?
Well, i must say that i am not a trader, i didn't get rich by trading so i can say i am the best one to give advices. Best tip that i can give is to check out croda and gevlon's blogs: marketsforISK and Greedy Goblin . They thrived in New Eden by trading and both have some good tips to use when trading, but most times trading means searching for an item that has a good profit margin (between 10% to 1000%), sells at a medium pace (less trafic = more profit but also more time for selling) and don't needs much order babysitting (of course, you can let your orders in the same level for more time but if you have competition, you won't sell your item too soon).
With minimum skills and time you can make a really good profit by doing almost nothing, this is mostly used by alts to fund the fun on main account and if you don't love number and economics i suggest to don't follow this career on a main.
Future - i want to be a trader!
I plan to open an alt character on my main account and use him as ISK source, but i am not sure at this moment if i want that number roller coster again, i will see...
But if you like numbers, and want to make easy ISK, then trading is for you, as the skills aren't so important, you need them when you have high capital.
That's it for today, what career would you like to hear abou next time?