I know basically zero about Ethereum, block chain etc. I have Augur reps. I have been asked to create an Ethereum address for the sale augur site. I don't have the slightest idea how to generate an address and or where to create an account for Ethereum. How to create an Ethereum address?
MetaMask was recently announced and will be faster than Mist (mentioned in other answer) since MetaMask is a Chrome extension and does not use a local copy of the blockchain.
This video is 3 minutes long, but you have all that you need to get an Ethereum address in the first minute:
Make sure to keep the 12 words secure and have backups of it. (Also switch to the "main network" if you want to send and receive real Ether.)
Finally, it would still be a good idea to read and familiarize yourself with the "Account Management" and other sections http://ethdocs.org.
Installing Mist will give you a main account, and follow the section "Using Mist Ethereum wallet":
Use the "main network".
As the above link's final step says, you can also click ADD ACCOUNT to create more. Each account is an Ethereum address, and choose whichever you want to use for Augur.
Each time you create an account, make sure to store the password securely and have several backups of it.
Make sure to also back up your accounts using Mist. Loss of any passwords or backup files, will mean loss of all reps and Ether that the account contains. Having a password without a backup of the keys is useless, and having a backup without a password is also useless (since the backup is encrypted).
The above is a quick way to get set up, and you should read and familiarize yourself with the "Account Management" section and others from the link above.
Mist is a desktop application, and Metamask is a chrome extension. These are outlined in other answers.
In the case of EthTools.com, I have created a video outlining how to create an address. Once you have created an address, you can export a keyfile and 'use' that address with Mist (on your desktop). You are also given a Mnemonic code which you can use to load you wallet on other tools like MyEtherWallet, and Jaxx.
Using MyEtherWallet, you simply need to visit their website, input a password and click 'Create New Wallet'.
As a more general explanation, an Ethereum address (or wallet) is simply a 64 character hex string generated subject to various rules defined in the Ethereum yellow paper.
As such anyone, or any product can generate an address by simply following these rules. The clients in these answers do that for you.