What are some good easy to use software packages to simulate circuits?
Ideally with a large library of IC's etc. I guess arduino simulation is out of the question, but to help design amplifiers and multiplexers etc.
Circuit wizard is meant to be a good simulation software; it also has PCB design and auto-routing, schematic design tools, and we have used it to program PICs ( 
) at school. The only downside is that you have to pay for it, and I would have thought it will be expensive...
On the bright side, there are free ones available, like 5SPICE. The downside to these is that they always seem hard to use.
Cost vs. usability - it's all a balancing act.
Onions.
If you are on windows LTspice is very easy to get going.
There are models for all of the Linear Technology parts.
If you want an open-source package you can use gschem (gEDA package)
- ngspice. Due to copyrights you have to download the models
from the manufacturer websites.
(* jcl *)
Circuit Wizard looks like more the type of software I am after - The only thing lacking is some components by the looks of things.
I have looked at LTspice before, but it scared me off!
Fritzing, looks good for Arduino PCB design, but no simulation.
sprint layout is easy to use and looks nice aswell 57 bucks not bad compared to wizards $100 plus