There are times when you need to fathom out what methods and properties an object has. The best way to do this is load the interactive PowerShell console and store the object in a variable like $Obj then you can do this:
$Obj | Get-Member
Get-Member -InputObject $Obj
Both of those lines do the same thing. If you are using a PowerShell compatible IDE then your IDE should do this for you.
You can filter your output as follows:
Get-Member -InputObject $Obj -MemberType property
Get-Member -InputObject $Obj -MemberType method
See Get-Member for more information.

Custom Objects

There is a very good introduction to writing custom objects at Powershell: Everything you wanted to know about PSCustomObject.