i work at a discount brokerage.
there are better entry level opps you should seek out first, but i'll assume you already did that.
it all really depends on how much you want to learn. i consider working at a DB an intro to fin. markets since you come across a wide variety of fin. products. if you have very little experience in markets, it might give you a chance to know how options, bonds, foreign exchange and securities trade. depending on where you work, you also have ample time to surf the internet and read market news (my fave part of the job). therefore, if you really want to learn something simple, you definitely have the time to do so. like i said, its introduction in its most basic form.
its more then just taking the orders though it doesn't get complicated outside of dealing with 20 open option orders and having to calculate the required margin. you have to understand the things a bit. for instance, if the client wants to put together an option spread, you have to know how to do it and understand what's going on. laddering a bond portfolio, looking into mutual funds and talking to clients about it. basic stuff, you will definitely learn about fin. products.
another benefit you get is you get to talk to a lot of clients. this is my first job so getting that experience was important and I DID learn a lot in dealing with customers. it also teaches you a bit how to deal with rushing clients who are yelling at you to put something through. at first, it was tough, now i'm getting the hang of it.
the bad part. first, much of your job is going to be centred around customer service and dealing with client issues not related to markets (their margin is messed up, someone didn't put a trade in correctly, or send me some money to my account, check what i sold my stock at). they're annoying because customers are annoyed. depending on where you work, you might be forced to push for other products.
secondly, if you're ambitious, its going to really annoy you to read about things that you want to be doing. you end up thinking all the time, i just want to read about economics or companies instead of taking calls. in other words, things are too simple after awhile and becomes very repetitive if you just do the job.
lastly, the pay sucks (40k plus bonus=approx 43k w/ overtime 45k).
I would take DB over several other entry level jobs especially if i was under 24 years old. have you looked into ibanking?
finally, you mentioned something about being a trader. Not sure about doing DB to get closer. they're two completely different things. 50% of the people i work with who are ambitious are looking to be traders. however, i have never heard of anybody from my department ending up there. one of my manager has a connection there and is giong, but that's it. if you're looking to be a trader, i think anohter route mgiht be better cause DB problably won't get you there, at least not from what I can see.
i work in Canada btw so things can be diff. if you're in the US.