After you see your banner, which will have you forum name near it, first you:

1) Right click the Sig/Banner

2) After That, you highlight the address(URL)

3) Than you right click the highlighted adress and click copy

4) After that is done, you go where that address is needed and paste...

Its pretty simple once you get the hang of it

To save the Sig/Banner to your computer(PC):

1) Right Click The Banner

2) Click Save As

3) Pick where you want to save the Sig/Banner

4) Pick a name for it and click ok