I'm going to use a Google Doc but you could do the same in MS Word if you like. So open up a blank doc.
Create a grid with the amount of rows and columns you want in your signature block (doesn't have to be perfect, we can add or remove more later):
Get your widths correct and merge rows/columns that you want to make a larger form.
Example: If you wanted your head image on the left, then make the left column narrower (box-like) then vertically merge all the rows in that column so you get a nice space to plonk your image.
Move your cell table to far left of the page to avoid a big margin on the left when copying and pasting into Gmail
Get your cells arranged and lined up as you wish, remember to merge the cells you want to make bigger with their neighbours by selecting the cells you want to merge and right click, select merge.
For the left cell I want to add a picture so making the cell content align vertically in the center is essential
Add your images to the fields and text, style as desired
Right click on your images and select Link, then insert your link in the text field (Note: there is a bug where the image options stays in front of the link text box so best to have the link copied already to easily paste into the field instead of typing)
Hide the lines of your grid
Paste it into your signature section and click SAVE down the bottom of the page.
Voila!
Hope this saves you lots of heartache.
If you don't want to go through all that by yourself, just steal mine, here is the doc with the template I used for this demo, enjoy.