Getting help
Depending on your problem, there are different places to get help.
Connection related problems
Before doing anything else, you should read the Network Configuration guide in the wiki.
Read the guide thoroughly and follow its instructions meticulously, it contains all the necessary information. Following the guide saves both you as well as the support staff a lot of time.
The wiki
You can use the wiki to find answers to common problems.
Feel free to contribute to the wiki, but remember that a wiki is there to provide solutions, not to ask questions.
Some pages of interest:
The knowledge base
You can find a lot of useful information in the knowledge base for both FileZilla and FileZilla Pro.
The forums
You can ask your questions in the forums if you need further help.
Before posting, use the search function, most likely your question has been answered before.
Be verbose in your posting and describe your problem in detail. Always state your operating system and the version of FileZilla you're using. Attach logs to your posting if possible.