Drupal 7.x

First off, let me apologize and say that I'm completely new to Drupal. I've read through the documentation, but have had some trouble following everything as it seems much is not in reference to Drupal 7. To help me understand Drupal, I've decided to start on a small project and work my way up from there; this project was an address book. I found this mini guide: http://drupal.org/node/86165 and have tried to do much of what the guide said, but my requirements are not the same as the user who asked that question and I have hit a roadblock.

Let me list my requirements:
1. I have clients (not Drupal Users) and, at a basic level, they need to have First Name, Last Name, and a few other basic fields.
2. I have addresses, they need to be related to clients in a many-to-one relationship (i.e. one client could have many addresses.
3. I need to be able to add new clients and for existing clients I need to be able to add (or remove) addresses for them.

Just got two error messages, one a recurring one. Can anyone help? messages below:

I need to allow my site contributors to post code that the other registered users can copy into their own websites that includes a customized URL.

We are providing buttons and banners that link to a web survey, and the URL in the code displayed next to the sample button/banner needs to have the correct suffix appended when viewed by the registered users.

For example, I'd like a contributer to be able to type in:

I would like to upgrade my drupal 6.x to 7.0.
I have made the steps 1-13 of the UPGRADE.txt. The mysite.com/update.php is started. It has found, that there are ca 140 issues to update. It has started to do them. But when it's arrived az 70% - "Updating system module", it's stucked with no error message. (I have waited half an hour.) :(

I'm getting the following errors when I go to create content:

Notice: Undefined index: description in field_multiple_value_form() (line 156 of /var/www/modules/field/field.form.inc).
Notice: Undefined index: required in field_multiple_value_form() (line 178 of /var/www/modules/field/field.form.inc).
Notice: Undefined index: required in field_multiple_value_form() (line 207 of /var/www/modules/field/field.form.inc).

Any ideas?

Please excuse me if my query has already been asked n number of times -- I am a beginner and enjoying learning Drupal.

1. I have created a new content type: Gallery Formatter, created a few image galleries and a block (ImageGalleryBlock) that contains list of image galleries.

2. Similarly, I have created a block that displays list of Articles I have posted.

3. I display both these blocks in the sidebar and am able to display the corresponding content on clicking a link in the blocks.