Hey, I know how to link text in your sig. I can teach first, but you'll have to work up your post number.
First, type the text you want. Then, you click the 'Insert Link' button, then you copy-&-paste the URL of the website you wanna link to & paste it in the column provided.
Tadah, you got your own linked word in your sig. Well, sometimes, you just gotta experiment around with these sort of things. Happy posting & linking.