SimpleThings:
I have regular multimeter ,I want to do this for a college project , also what attentuator and amplifier do you suggest.
I was thinking about resistive divider , but what if there will be voltage > 5V at analog pin to the GND , it could destroy the pin or even uC.
Range switching manually is acceptable.
Don't worry about it too much. There are protective diodes to keep this from happening. It's gonna be alright with 100k resistors. In fact, even Atmel says this is okay...
They say it here
And I'd suggest using a simple opamp for reading the current. LM358 will be okay. Just switch in different feedback resistors to change gain. Don't forget to measure the offset voltage and correct for it in software!