I just cooked my first recently...and I have to say...its a lot more simple than it sounds. But first ROMs...I ran two different ROMs for sometime...I started with Y4J's Clean ROM's...lovely, fast, clean, and stable. Then I switched to KK's loaded...from 1.5 to 2.0. His ROM's are truly LOADED...but still fast and stable.
Now, I have that happy medium of cooking my own. Two kitchens that I found easy and simple to use. Calkulin's and eRice's. cooking a ROM is pretty simple. both these kitchens has step by step prompts. You get to pick the "programs" / OEM's cooked into the ROM.
Download a kitchen and just check it out without burning the ROM onto your phone...you'll see
TouchFlo 3D (TF3D) is the User Interface that HTC put ON TOP of Windows Mobile 6.1. There are plenty of other different kinds of interface out there...SPB Mobile Shell 3.0 to name one. It's just different ways to interface(act) with your device. Most of these UI apps out there are finger scolling friendly. Windows Mobile 6.5 (the "upgrade" to the current O/S) has a finger scolling user interface built in called (Titanium)