Illustrations that I have added to Wikimedia Commons and inserted in some articles:
Illustration of the electric field surrounding a positive (red) and a negative (green) charge (click for larger image). I inserted this illustration in the Electric field article.
Illustration of the electric field surrounding two equal charges (click for larger image).
Illustration of the electric field surrounding one positive charge (click for larger image). I'm not quite satisfied with this one, but I don't see any article where it would be obvious to use, so I won't improve it just now.
There is a mentorship module on the newcomer home page, that pairs each newcomer with an experienced user and provides a simple way to post questions on their mentor's talk page.
To activate the newcomer home page feature, do this:
1) Go to Special:Preferences
2) Click the User profile tab
3) Scroll down to Newcomer editor features
4) Check the box Display newcomer homepage
5) Click Save at the bottom of the page
A link to the newcomer home page will appear at the top your user page and user talk page. The mentor box is on that home page. Have fun!