How to put an image into an email signature?

I want to put an image into my email signature with my contact details next to, not below, the image. Nothing I try is working! On my PC I made a table with no borders, put the image in one cell and my details in the other and was easily able to copy it into an email, and to set it up as an email signature. On my mac I've managed to set up one signature but it won't add another (I've created a 2nd but in the email the 2nd doesn't register as an option), and putting an image in just istn' working.