Getting started with EC2

To get start with EC2, you have to create an account in EC2 site.
After you successfully create your EC2 account from the amazon site, there are several steps to actually use EC2 instances.

Step1) Create X.509 certificate
Login to you Amazon account and AWS access identifiers page. In the X.509 certificate section, click Create New. Also Download your Certificate and store ot into your desktop safely.
mkdir .ec2
cd .ec2
mv ~/Desktop/*.pem .

Step2) Download EC2 command line tools. http://developer.amazonwebservices.com/connect/entry.jspa?externalID=351&categoryID=88
And unzip files under the ec2 directory.
mv ~/Desktop/ec2-api-tools.zip .
unzip ec2-api-tools.zip

Step3) Modify your shell script file. In my .bashrc file, I added,
export EC2_HOME=~/.ec2
export PATH=$PATH:$EC2_HOME/bin
export EC2_PRIVATE_KEY=pk-YOURKEYNAME.pem
export EC2_CERT=cert-YOURKEYNAME.pem

Step 4) Generate key pair to ssh to your instance
cd .ec2
ec2-add-keypair pstam-keypair > id_rsa-pstam-keypair

Step 5) Now select your new instance
ec2-describe-images -o amazon

Step 6) Create an instance
ec2-run-instances ami-6138dd08 -k pstam-keypair

Step 7) Check the description of the instance
Loading an instance takes some time. If you see the valid URL for the instance in the description of the instance, it's ready to access.
To check the description,
ec2-describe-instances

Step 8) Open the ports for ssh and http connection
You have to open some of the port you will allow to outside of the instances.
ec2-authorize default -p 22
ec2-authorize default -p 80

After this you can ssh to your instance.

Step 9) SSH to your instance
ssh -i id_rsa-pstam-keypair root@ec2-XXX-XXX-XXX-XXX.z-2.compute-1.amazonaws.com

Step 10) Getting a static IP address
For your application, sometimes you need a static IP address for your instance.
First you have to assign a static IP and tie the address to your instance.
ec2-allocate-address
ec2-associate-address -i i-yourinstance XXX.XXX.XXX.XXX

Step 11) Now you can SSH to your instance like to other remote machine.
ssh root@XXX.XXX.XXX.XXX

Step 12) Terminate Instance
ec2-terminate-instances i-yourinstance