How do I make text to be replaced with my own images, like Home, upload, etc?
You didn't give very much info to go on so the best I can do is give you a generic answer. Next time give us a link to your gallery or zip it up and attach it with your post. This answer depends on the theme you're using. Here it is for the upload link. Of course you'll need to add styling and positioning if necessary.
<a href="{UPL_PIC_TGT}" title="{UPL_PIC_TITLE}"><img src="./themes/your_theme/images/upload.gif" title={UPL_PIC_LNK} /></a>
I make my theme based off classic theme. So, if there is anything I should know,
do as suggested and post a link to your gallery!