electronic simulatiion softwares

Some of the best electronic simulation softwares I recommend are LTSpice4,switchCAD,Micro-cap.The schematics can also be saved as images in these softwares.If you are using Linux then ktechlab is the best choice.ktechlab is simple and only some basic components are supported.Some other include Multisim and Microsim.

Of
all these I suggest micro-cap because it is simple and the software
comes with lots of example circuits,which makes it easy to learn.For
learning VHDL Active-HDL is good and it comes with a nice tutorial on VHDL.You can learn VHDL easily.

screen shot of LTSPICE

screen shot of MICRO-CAP

screen shot of Active-HDL

some other electronic simulation softwares

circuitshop

easysim