I've been playing around with C# console applications for about a year and I want to move on to creating GUI applications. I have never done any GUI development besides basic Java applications, but I want to continue using C#. Should I start learning Windows Forms or jump straight to WPF? Is there a huge difference? Does WPF build on top of Windows Forms or are they totally different?
If you're just starting out, jump straight into WPF.
It will allow you to get starting making rich interfaces using mark-up to define your interface without teaching you the possible bad habits (for WPF) that you'd learn from Windows Forms.