Using an arduino to plot two curves

I would like to use arduino to plot two curves,that show the resistance according to time [t(s)] and according to the current[I(A)]
Something like what i attached
If you have any links that are relevant and might help they would be greatly appreciated!(Sorry if it`s too much of a newbie question or bad english)

Where will the data be plotted? A PC plotting program, graphic LCD, ...?

In what form will the data be? Array(s) of floats, strings, CSV, ...?

Something like what i attached

Nothing yet.

This is what i was talking about, sorry I couldn`t attach the file!
Also i want the data to be plotted to a PC plotting program like Matlab or Excel

(moderator added a few returns)

A serial port is how the Arduino can communicate with the outside world. On the Arduino side you gather the data and format the data into a packet to be sent over the serial port. You must have a application on the PC side to receive and parse the data. That part is beyond my experience in terms of Matlab or Excel.

Do you have code to read resistance and current?