Well the individual instructions will be different per piece of software. Normally you can find documentation and help on the websites. For example drupal has a tutorial here:
http://drupal.org/node/258
In all honesty, without sounding like I'm trying to get a bit of work out of you, you'd be better off hiring someone to install these features for you if you are computer illiterate. Then that person would perhaps be able to help guide you through what they did and give you a better understanding of how these things work. However, there's plenty of literature out there if you're willing to look for it