Newbie Needing Help

Ok guys, im going to be flat out honest, Im new to this whole database thing. I've been doing a lot of studying and Decided that I am going to try my hands at a real simple and straight foward database. It seemed fairly simple but i guess not so im asking for help. I think my problem lies in understanding how the keys work, and what exactly they do for the database itself. And two the relationships, im not really sure of, i understand how to set them, but again i dont know what they do for the database in the end. Ok so heres what i got:

The object of this DB was to collect, store, retrieve, edit and display data for a fictious Print center that deals with Black & White copies and Color Copies.

3 tables:

Company
Customer
Job

these tables contain:

Company Table:
CompanyID Set to AutoNumber *SET AND PRIMARY KEY*
CompanyName Set to Text
Address Set to text
City Set to text
State Set to text with 2 Character limit for input
ZipCode Set to text with 5 characrtr input
Description Set to Memo
Webaddress Set to hyperlink

Customer Table:
CustomerAccountNumber Set to autonumber *SET AND PRIMARY KEY*
CompanyName Set to Text
JobNumber Set to number
FirstName set to text
LastName Set to text
PhoneNumber Set to text with mask set
FaxNumber Set to Text with mask set
Email adddress Set to text

Job Table:
Jobnumber Set to autonumber *SET AND PRIMARY KEY*
Jobname set to text
Jobtype Set to text
JobDescription Set to memo
DueDate Set to Date and time

Ok now hers the relationships I set up:

Company Table: CompanyID ------> Customer table:CompanyName

Customertable:JobNumber ------> JobTable:JobNumber

I tried and thought this would keep things simple but for some reason when i go to create my querys, i get this thing telling me that i have other data from another tabel and cant be edited, i figured out that i had to put the job in first to get a job number and when i go to enter the customers information i have to manually enter the job number in. (Kinda Sucks) I entered some sample data, and tried to make a form, I used the autoform and created a general form but when I flip to the last record in the DataBase it wont let me enter any new information, I thought i was suppose to do that, so i went to the table properties and set the table to Data Enrty Only, and i still couldnt enter new data.

:confused: Ok so theres my problem, I made a boat with duct tape and now im wondering why im sinking to the bottom. Any help would be GREATLY APPRECIATED and if possible a broken down real world explanation on how the keys and relationships work, and what they actually do for the database. I also probably didnt set up the data in the fields correctly, I was trying to normalize everything but im not sure.

Thanks guys! Im really greatful for any help you can offer! ~[MikE]~ :)