I'm accustomed to using the Help (or Man) command to obtain help on PowerShell. Technically, these ARE commands - not aliases (you'll see Help if you run Dir Function:, and Man is an alias to help). They bundle up some functionality, like paginating the output, and leverage the native Get-Help cmdlet under the hood. But there can be some significant advantages in knowing the options for using Get-Help directly.
First of all, never forget that Get-Help supports parameters like -Full and -Online, which display complete help and the online (and likely more up-to-date and correct) versions of the help. You can also add -Examples to see examples of how to use a command. The -name parameter specifies what you want help for, and it accepts wildcards - making commands like this valid:
Get-Help -name *service*
But you can restrict the help that comes back by using the -Category parameter, specifying Alias, Cmdlet, Provider, or HelpFile. For example, to just focus on the help content related to concepts and techniques, you want HelpFile:
Get-Help -name *param* -category helpful
You can also get help for a specific parameter. This can be incredibly useful. For example, New-ADUser (part of the ActiveDirectory module included with Windows Server 2008 R2) has a crazy number of parameters. When I want to look up a specific one, having to use the -full parameter and scroll through pages of output is time-consuming. Instead, I can just grab the parameter I want:
Get-Help -name New-ADUser -parameter Name
That accepts wildcards, too, so you can provide something like "-parameter *n*" to get all the parameters containing the letter "n," if that's what you were after. It can be a good way to quickly locate a parameter that you know exists, but that you're not sure of the exact name for.
You can use all of these with the shorter "help" command - no need to type the extra four characters for "Get-Help." But it's useful to know about all of the underlying function that the command supports.