flow chart diagrams : tools / best practices

Are there any free online tools out there to make visio kind of diagrams. I would like to practice my flowchart skills. Are there any good sites or books or articles out there that discuss best practices for flowchart diagrams.

From stackoverflow

• Dia is an open source option: http://projects.gnome.org/dia/

• +1 for Dia. It's also cross-platform, which won me over. Another advantage of Dia is that the diagrams are stored in compressed XML.

  I had a project where I needed to diagram something in the database, and I was able to write a program to create Dia-compatible XML from the database, which saved me a HELL of a lot of typing and drawing. I just had to reposition and resize the objects.

• http://www.umlgraph.org/

  Found no other better solution. Program your charts. Makes beautiful sequence diagrams.

• Gliffy is an online flowcharthing program.

  Personally I use Dia, an open source Visio kind of clone (it works under Windows, Linux and MacOSX).

• Open Office includes a program call Draw which is really nice.

• Already answered here;

  Here is some:

  • StarUML - http://staruml.sourceforge.net/en/ (Free)

  • Enterprise Architect from Sparx Systems (Not free)

  • Violet

  • Umbrello UML

  • ArgoUML

  • Dia

  Here is a complete list of over 50 UML designer (free and not) Wikipedia list:

  http://en.wikipedia.org/wiki/List_of_UML_tools