So, how to start. What does it take to make $10 a week or what will your hardware/GPU's accomplish in producing Bitcoin?
What are your cards potential?
2 X 5850
First go here: https://en.bitcoin.it/wiki/Mining_Hardware_Comparison
This will give you an idea of what others can do with the card you post.
It looks like your card can produce between 240 MH/s - 431 MH/s, of course we like higher numbers.
The average hashrate for all 5850 listed is 342.58 MH/s.
The average of the top 13 is 400.6 MH/s (This is the number you can hope to achieve with better tuning.)
So we can say 1 card has a potential to produce 400 meghashes per second, how many Bitcoins is that?
Go here: http://www.alloscomp.com/bitcoin/calculator.php
In box #2 put in the hash rate of your card or the number you hope to achieve.
Then go here: https://mtgox.com/
(You can choose low, high or average.) I chose average.
Now, enter the current price in dollars that 1 BTC is trading for into box #3 and press "Calculate".
per Day ฿0.29 $1.68
per Week ฿2.04 $11.76
per Month ฿8.87 $51.06
This means that one 5850 card, at the current difficulty rate, could produce $11.76 US per week. If you have 2 cards than that is twice as good.