First, make sure you are looking for your book in the proper way. The most precise way to search for a book on any e-retailer's website is via the ISBN. You can locate your ISBN on the back of your book under the barcode.
Next, realize it can sometimes take at least 14 business days from the date of publication for a title to be distributed to Ingram. Ingram, in turn, distributes the digital information (called meta data) about your book to other wholesale and retail partners. Each of these other partners updates their catalogs and listings at different schedules which are out of our control.
It could take an additional 4-6 weeks from the date the title is available at Ingram for it to be available online. That means in some cases (when Barnes & Noble is particularly busy or backed-up, for example), that it could take up to 2 months for your book and all its information to be online.
Information for your book may become available in "pieces." That means your book may be available for sale before the cover is shown, or vice versa. It all works itself out, typically within the time frame above, and is often much faster.
These time frames and processes are up to each individual wholesale and retail partner, not Outskirts Press. We provide the distribution information to Ingram at the time each Diamond, Pearl, Ruby, and Sapphire book is published. Once that is complete, it is in the hands of each of the wholesalers and retailers to collect that digital meta data and update their records.
Full availability via some of these distribution channels is also dependent upon the Trade Discount you set for your book. No retailer or wholesaler is ever obligated to carry every book (although BarnesAndNoble.com typically does).