I'm a web developer who mostly works with the LAMP stack when it comes to my own projects. Most of the time I just start coding on a project and fixing bugs and adding features as I go along. Often I'll try to use an existing solution such as Wordpress or Drupal. Now that I'm thinking of creating my own web application with businesses as the target group, I feel there's a need for proper analysis and design. Something lightweight for a one person project and still solid enough to handle requirements, user interfaces, security, etc. If you could recommend methodologies and literature I would be grateful.