To create the listing of a product, here is what you should do.
Step 1: Click on the "List" tab at top of your profile page as shown in this screenshot => http://prntscr.com/hf3thv
Step 2: Insert one or two images of your product, add name and description of the product and select a relevant category as shown in this screenshot => http://prntscr.com/hf3ul9
Step 3: Select settings as shown here => http://prntscr.com/hf3vtc
You need to set up the settings part of your listing in two steps. The first part is sorting out the type of listing, sell, share, or both, => http://prntscr.com/klxlnw
Step 4: Save the settings and on the confirmation page next, read and confirm your work, check the agree to terms and conditions box and click "Sell it now" to publish your action immediately. Shown Here ==> http://prntscr.com/l99yot
Step 5: Once you have published your listing, the final pages allow you to establish buyer requirements and add shipping information. Shown Here ==> http://prntscr.com/dwrnnv
To make sure that your products are not rejected, read these marketplace guidelines before listing something up for sale: http://www.empowr.com/Provide/Listing/ModerationRejectionReasons.aspx
REQUIRED WHEN APPLICABLE:
-UPC Barcode for DVDs, Games, CDs
-ISBN#, author, publisher, page count, paperback/hardcover for books, magazines
-Volume (grams, ml) for Health&Beauty items
-The expiration date for Food, Health&Beauty items
-Sizes for clothes, shoes, rings, dial dimensions and band length for watches
-All technical specifications on consumer electronics like phones, TVs, blender, washing machine
If you missed any of above - your listings will be rejected.