Magento Installation Guide against 1and1 hosting

1. Check Magento Requirements (Check PHP Version, Extensions and MySQL Version Number)
2. Setup a MySQL 5 Database
3. Download, Upload and Unpack Latest Magento Package (Use full package if possible, not the installer)
4. Move the Magento Folders & Files to appropriate location (eg: http://www.your_domain.com/magento OR http://www.your_domain.com)
5. CHMOD 777 the following: [file] magento/var/.htaccess [dir] magento/app/etc [dir] magento/var [dir] magento/media
6. Configure .htaccess located at magento/.htaccess with the following:

AddType x-mapp-php .php4
AddType x-mapp-php5 .php
AddHandler x-mapp-php .php4
AddHandler x-mapp-php5 .php

Configure the RewriteBase as well according to the following rules:
eg: http://www.your_domain.com

RewriteBase /

eg: http://www.your_domain.com/magento

RewriteBase /magento/

7. Run the installation by going to: http://www.your_domain.com/magento/index.php/install or http://www.your_domain.com/index.php/install or etc.
8. Setup is very easy.
- Select locale settings.
- Type in MySQL DB Info.
- Checkmark “Use Web Server (Apache) Rewrites”.
- Checkmark “Use Secure URLs (SSL)”...IF YOU HAVE SSL CERTIFICATE INSTALLED (eg: https:// access)
- NOTE: AFTER THIS IT MAY GIVE AN ERROR 500, JUST HIT THE BACK BUTTON AND CONTINUE AS NORMAL. (You can double check the DB to ensure all the tables are in, which it should be. There should be a ton of tables all the way down to tables starting with a ‘w’).
- Type in Admin Information and Create Encryption Key.
9. Access (depending on where you installed it):
- Frontend: http://www.your_domain.com/magento OR http://www.your_domain.com
- Backend: http://www.your_domain.com/magento/admin OR http://www.your_domain.com/admin

source: http://www.magentocommerce.com/boards/viewthread/3462/