18300 three quick updates

hello i'm in need of 3 updates pretty quickly. 1 - i have an invoicing script that i can press a notify link and it will email the customer a notication that they have an invoice that is due. Well this script quit working for some reason but i want this script to be a bit different anyway. I want it to AUTOMATICALLY email the customer their invoice on the duedate and copy me an email so i can make sure they received it. I have cpanel and cron so i know this can work. 2 - my admin panel is getting a lot of entries so i'm in need of page links instead of showing all the entries on one page as it does now. I like how [login to view URL] does it when your looking at the friends... 1 - 10 11 12 13 14 - of 23021 so something like that...and how many entries display on each page is changed by the user in their preferences...i already set that part up. 3 - this is the easiest one...i have a guestbook that was 3 files...i recently compiled it into one file with the cmd=view or cmd=home etc...almost all of the links work fine but 5 of the links i cannot get to work correctly for the life of me...it's probably a 5 minute fix i'm just no php programmer. Please ask questions if needed..and please do not post if you can't deliver pretty quickly. Thanks