Assemble your resources. [July 23, 2012, 8:50 a.m.]
First, make sure you know where you found all your content. Make note of things like the website URL and the creator. Also, what open license did it have? When was it created and/or pubilshed? These are important pieces to keep track of so that others can get back to the source information.
Remember that with CC licenses, you don't need to ask the original creators for permission to use their work as long as you follow the terms and conditions of the license. But that doesn't mean you can't thank them or let them know you're using it! Shout-outs on Twitter or in the comments section of a blog or Flickr image are nice practices.
You may discover that you don't have the rights to use every resource you found. Which resources do not give you the rights you want? You might want to do another search to find appropriately licensed materials to replace those. Remember, each open license carries with it different conditions, eg. if you intend to make a profit with the final product, you would need to find content without the "noncommercial" or NC license clause.
Lastly, consider the places where you found your resources. Did you like anything about some of the websites and/or platforms where the resources were hosted? For example, did the platform make it easier for you to identify the CC or other open license of the resource? You may want to keep a list of the sites you liked for sharing back your resulting work.