Have you looked at the FAQ/Tutorials page on the MyStuff2 website? There are answers to how to setup a category, how to deal wih No Value appearing, and how to setup the product mappings for Amazon integration.
Please see http://www.maddysoft.com/iphone/mystuff/tutorials.php
MyStuff2 shows [No Value] for an item on an item list under a few different conditions.
The item is assigned to a category that has no attributes.
The item is assigned to a category with attributes but you have not entered any values into any of the attributes for the item.
Even if you entered some values for one or more category attributes you may still see [No Value]. The value displayed in the item list is the item's title. The item's title is defined on the Item Display section of the category. If the item doesn't have any values for any of the attributes setup under the category's Item Display then [No Value] is displayed.
Please note that values entered into custom item attributes do not count. Also remember that custom item attributes should rarely be used. If you find that you are adding them to most of your items then you should reconsider using appropriate category attributes.
I also read the tutorial about how to create your own category:
One of the many strengths of MyStuff2 is that it can be setup to keep track of whatever information you want, not just those of the sample categories. The following basic steps can be used to create and setup your own category. Much of this information also applies to making changes to an existing category.
To add a new category you must return to the main Categories screen.
Tap the Edit button and tap the Add Category row. This brings you to the New Category screen.
At a minimum you need to give your new category a name and at least one attribute. Tap Add Attribute for each new attribute you wish to add to the category.
Most likely you want to configure the category's Item Display. This allows you to specify exactly how this category's items will be displayed on the Item List screen. This includes the title and subtitle lines as well as any colors you wish to use.
If you plan to use Amazon search or barcode scanning to add items to this new category then you need to setup the category's Product Mappings.
Once you have configured the new category tap the Save button. The new category will now appear on the Categories screen.
However the tutorial doesn't make clear how to assign the attributes.
Something as simple as "Name" doesn't appear to be an option in the attributes.
"Values" and "Attributes" mean nothing out of context (ie understanding what's supposed to be there). My apologies, I'm not intentionally being lazy but your tutorial is quite unclear as to what kind of data should be assigned and the best way to assign the data so that it flows effortlessly in sync with the Amazon data.
I bought your app because the barcode scanning works so much better than any other inventory app out there and with a collection of over 1200 CDs, 1500 books, & a few hundred games and movies this is a must have. However it seems far too complicated to simply set up a new category.
Have you considered doing a few video tutorials? That might help people who aren't as skilled at interpreting your written tutorials and based on some of the reviews on iTunes and comments in this forum the confusion isn't limited to just me. You might also consider doing a simplified version of the app for people who don't need the advanced functions, I'd certainly buy it.