Good resources for UI design patterns can be found just about anywhere nowadays on the Internet. When it comes to software you must be careful to adhere to the limits of what platform you are designing for. A lot of users already have predefined what they are used to, what they expect and what they like and don’t like.
Graphical user interfaces have not changed much since the beginning of the PC and the software that came along the Apple Lisa years ago. You should concentrate on providing high fidelity prototypes and mock-ups that should represent your design in the best light possible.
Some specialized prototyping tools that are popular on the market are: