Electrical software /CAD?

Hello there I need some program which will ease or accelerate the calculations of circuits. I am talking about very simple circuits - transistors, diodes, maybe a microprocessor etc. I am using Linux and have Windows. I know a few - oregano, qucs spice. I need something with a easy learning curve so I guess it will need a GUI. I don't have time to learn Verilog or VHDL or spice right now.