I'm trying to write some stuff about my argonian, Sal-Mak and I need some help. Basicly, Sal-Mak is an adventurer whos unpopular and aggresive, but I can't think up anything else.
Any ideas/hints/tips that could help?

well he could have a friend who lives around vvanderfell or a special enemy who you could also incorperate into his life. he could also have a preferred race he likes to associate with, or class. maybe he likes to drink alot and gets into bar fights, and hes been banned ffrom peligiad tavern or something.

Hmm, thinking, some good ideas....
Taverns is't his kind of thing, he loves to travel, get his hands on valuble stuff. And he hates slavers, he isn't a team player and he has a rough nature, so people generally don't like him so he does't speak to people much. But he is a very nasty fighter.
hmmm, thers some other things I need to add to his background before I cna write any stories about him.

maby he perposly searchs for withches just to kill them, or he makes orcs heads his trophies. a smuggler of dwemer artifacs maby?

Hmmm.....

What motivates your character - greed, revenge for something that happened in the past, searching for someone or something he lost? What happened to him in the past to make him the person he is today?

Work out the answers to those questions, then take it from there.

Motivation! Thats got me thinking, thanks Theta Orionis!
I'll put up the background very soon.

what about the motivation to track down his mothers owner or murderer

I'm working on it.....