Adding/Changing Navigation Buttons

I did find how to add a navigation button, but I would like to know what to put into the spaces. What I would like to do is change the home button to be directed to my website home page and add a forum button to direct to the forum page.

Add a link
Picture selected *
Redirection URL *
Alternative text *
Open in a new window
Items marked with a * are required unless stated otherwise.

Example: Picture selected, do I put the url link to the picture of my existing button, ie: my home button - do I put https://2img.net/i/fa/gothic/icon_mini_index_en.png or do I put the icon_mini_index_en.png in it?

Redirection I know is the url link to the page I want to go to with that button, right?

Alternative text - Do I type in the text that should show up on the new button??

Or, can you make me a forum button that matches the ones on my page??

Also, if I ever wanted to delete a navigation button, how would I do that??

Your help is much appreciated, as I am new at this.

Thank you,
wildchildz

heres an idea of what i think you mean
and yes the full url of image

Code:

[url=URL%20LINK%20HERE][img]FULL%20URL%20TO%20IMAGE[/img][/url]