Perhaps the most common error made by Python beginners is to forget that Python is case-sensitive, so that is the first thing to check.
This may be the second most common cause of problems, and the Python error messages often don't identify clearly lines that have mismatched parentheses (for example 3 opening parentheses and only 2 closing parentheses). Mismatched parentheses and the errors they generate often make it appear that there is a problem later in the script when in fact the problem is the mismatched parentheses.
You don't always need the brick to be connected to the internet but you sometimes do, such as when you want to update the ev3dev and Python libraries. The sharing of the PC's internet connection by Windows can sometimes fail - you will then get error messages when you try to use the internet from the brick. You can also know that you do NOT have a connection to the internet if Brickman tells you you are 'Connected'!! When the brick is connected to the internet, Brickman's networking page will say you are 'Online' rather than 'Connected'. Rather confusingly, 'Connected' means the brick is connected to the PC but NOT connected to the internet i.e. not 'online'. If you need to regain an internet connection from the brick you can try this:
Using Brickman to run scripts that use LCD screen is straightforward, but if you want to run the same scripts from SSH you need to carry out a few extra steps that are described at the bottom of this page.
If you are having lots of problems and you think it may be because your libraries are very out of date then you might want to upgrade them all. This should not be taken lightly because it may cause some of your programs to stop working because ev3dev is still being finalised and changes to ev3dev may cause your Python commands to fail. If you want to upgrade all your ev3dev libraries then visit THIS PAGE. Note that this upgrades ev3dev but not ev3 Python so it may also be necessary to update ev3 Python.
Password for 'sudo'
Any time you use 'sudo' (the equivalent of running a command as an administrator in Windows) you will be asked to enter the password for 'robot' which is 'maker' (case-sensitive).