How do I sell a steam account

I don't do much steam, but I need to get a lot of money for paypal so I can buy something in halo 3. What does digits refer to? I have an account with the following games. I know it isn't much, but Im not asking for a lot, and I don't know what is important in these sales.

Lost planet: extreme condition
Half life 2
half life 2 episode 1
half life 2 episode 2
half life 2 lost coast
portal
team fortress 2

Lost planet is installed, all others aren't. Is this worth anything?

i still have the activation number and cd of all the items

 

go in a server on tf2 open console and type status and see what teh digits are next to your name im guessing its a 8 dig so your account will be probably $7 tops

 

what do the digits mean?

 

here i copyed and pasted this from hypherne or whatever the fuck it is at the top Steam Digits:
Explanation: Steam digits are a series of numbers that represents your account. The lower the digit the more experience it shows, also the lower the digit the more the account is worth. Digits are considered the X's in Steam_ID:0:0:XXXXXXXX if there are 8 numbers after the last : there are 8 digits. 1 and 2 digits are not open to the public so if someone is selling one it is 99% chance of a scam. TO FIND STEAM DIGITS JOIN A VALVE GAME, GO INTO THE CONSOLE AND TYPE STATUS

 

I'll pay 3 dollars for it. add my msn in my sig if u interested.