apt-get install openssl
openssl genrsa -des3 -out server.key 2048
openssl req -new -key server.key -out server.csr
cp server.key server.key.com
openssl rsa -in server.key.com -out server.key 
openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt
mkdir /etc/apache2/ssl
cp server.crt /etc/apache2/ssl/apache.crt
cp server.key /etc/apache2/ssl/apache.key

will creating a new certification it will ask you questions like your company name and more. the fallowing lines are an example:

openssl req -new -key server.key -out server.csr

Enter pass phrase for server.key: myreallylongpassword
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [AU]:CA
State or Province Name (full name) [Some-State]:Quebec
Locality Name (eg, city) []:Montreal
Organization Name (eg, company) [Internet Widgits Pty Ltd]:Wireless Army
Organizational Unit Name (eg, section) []:IT-Security
Common Name (e.g. server FQDN or YOUR name) []:wirelessarmy.com
Email Address []:info@wirelessarmy.com

Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []: (optional) 
An optional company name []:Wireless Army

The "challenge password" requested as part of the CSR generation, and the pass phrase used to encrypt the secret key (requested at key generation time, or when a plain text key is later encrypted - and then requested again each time the SSL-enabled service that uses it starts up), are two separate and different things.
If you enter a challenge password you will be prompted for the password every time Apache starts or your server reboots.

now open the /etc/apache2/sites-availble
change the port from 80 to 443 the add fallowing lines beetween the <VirtualHost *:443> and </VirtualHost>

SSLEngine on
SSLCertificateFile /etc/apache2/ssl/apache.crt
SSLCertificateKeyFile /etc/apache2/ssl/apache.key

now you should run these commands

a2enmod ssl
a2ensite default-ssl
service apache2 reload
service apache2 restart

remember that because it's self signed people will see an error that says The site's security certificate is not trusted! and a button to go to site anyway. it's good for development processes but if you want to use it in a real world environment I believe that you should pay for it.