What is best CMS(Content Management System) hmm... really luqiud question, I have expirience with several CMS. The first one I used was "PHP website",  I found it non useful, for some reasons... My second attempt was Drupal, this one is more better, however common user can find it comlicated, because of admin area, to much mixed.. Also drupal needed to be patched after default installation.

I stoped on Mambo, as the others, Mambo is  free as well, and it has the biggest community to support the open source CMS, and it update often, you can easily find a lot of websites from teaching you how to use mambo, to hacking the codes to modify to the way you want it.

But your selection can be various, so here Five simple steps to choosing the right
Open Source CMS for your needs…

1. First, determine what kind of site you are looking to have. Is it a portal? Is it a blog?  Is it a static site for informational purposes?  It is a project collaboration area?  Is it one or a combination of all these things?  This is the single most important step in deciding where to go next as it determines how large a playing field you'll have to deal with.

2. Next, decide what features and functions you would like to use on this site.  Will it need to present static or dynamic information?  Will there be a need for an event calendar?  Will there be a need for an upload/download area?  What about an image gallery?  How about a poll or survey tool?  Will you be needing a translation function?  These are called "modules" or "plug-ins" and are typically add-ons to the core system (sometimes it is integrated as part of the base system) and can vary greatly from one system to the next.  More established systems will have a lot of support which translates to a wide variety of modules and plug-ins, but on the other hand they may not have current support and modules may be incompatible with newer releases.  Also it's important to note that just becausea system supports a particular function, it's still important to see how it works and make sure that's what you expected.  Different groups implement the same feature set in different ways and this is both a blessing and a curse.  It helps to list all the things you need and use that as your shopping list to test against and experiment with. The key word here is experiment because that's the best way to understand how useful it may be.

3. Once you determine the base system and the modules to add it's time to decide on the presentation of your site.  Most current systems utilize CSS (cascading style sheet) and templates that allow you to quickly update the look of
your site.  Sometimes this is referred to as the "skin" of the site.  The same content shown with different "skins" can have quite a dramatic impact and appearance.  One can be inviting, while another can be professional or silly.  It's
all up to your imagination.  The good news is that even if you aren't creative or artistically challenged there are plenty of resources around to help you.  These resources come in the form of templates and themes designed by more creative minds.  You can download these and add them to your site and really give your site a complete makeover. Some of the better CMS even allows the registered user to pick and choose the "skin" or theme of your site.  Sometimes this is referred to as  "personalization."  For example, you might be able to customize the "welcome" message when you login to the system to add your name as a greeting or change the color of the text or select the modules you would like to see when you login.  All these features are handy and add an element of flexibility for both the user and you.  Users will be pleasantly surprised by the ability to customize their "view" and you get credit for setting up an environment where users have more control without breaking or reprogramming the structure of your site.

4. Having the defined the site's presentation layer you're now off to focus on the meat of your system - the content (for the vegetarians in the house, your meat may be soy-based).  As you may have read again and again that content is king. Well, it's true.  Without content no matter how pretty a site looks, it's usefulness and utility will soon fade and no one will want to return for another visit.  There's only so many times you will be interested in visiting a site that doesn't have the information that you're looking for. Information can come in many forms, it may be practical, it maybe humor, it may be knowledge, it may be a cookie recipe, or it may even be how to build a better mousetrap.  The point is that information helps to keep your audience coming back.  It is like candy for little kids, that's got to be a knowledge payload or your site will suffer a slow, spiraling death.  To avoid this is really simple, write interesting articles, tell a story, share your pictures, present your research, allow submission of content, and always keep
the juices flowing by expanding your site with new ideas and thoughts.  It also depends on what kind of system you have in place, if it's a blog provide daily commentaries, if it's a news site then aggregate news from other sources using news exchange mechanism like RSS, and if it's a forum create topics that encourage lively discussions.  Nothing is more frustrating then visiting a site that doesn't have a point of view and/or some sort of benefit to the visitor.  Everyone likes to discover or learn something new and when they find that at your site, they'll keep coming back again and again.

5. Now that you've got this all down there's only one thing left to consider and that is on-going maintenance and renewal.  When choosing a CMS think about how you'll be maintaining the system as it grows. What happens to the content when it grows old?  Will it be archived and it be available online?  Or will that even be necessary or desired?  Will there be a way to restore the whole system to another area or even to a whole separate system if your server should crash?  Different CMS handles these differently; some include an export function while others require a manual batch to be run periodically to capture the changes.  While these aren't sexy topics to think about, it's necessary to plan for worst-case scenarios before it happens because at that point if you don't have already have
a plan in place it's too late.  Consider talking to other administrators and joining in discussions to get a better handle on this issue.  There are a lot of considerations to keep in mind and that is beyond the scope of this article (stay tuned for future articles on the topic).  Just keep these in mind and don't forget warned you to plan ahead.