You can find deck design ideas in home renovation or deck building books. You can find them in home improvement stores such as lee valley or home depot. They do not only provide the correct building techniques but also very stylish and modern designs.
You can get patio deck designs from private contracting companies that are local to you. You can also get design ideas from several library books on designs.
This is great book I found: http://www.amazon.com/Deck-Designs-Railings-Planters-Benches/dp/1580110703. It's fairly cheap too (especially if it's used!)
"1001 ideas for decks" from Joseph Provey is a good one. There are a few others such as "Deck designs" from Steve Cory, "The deck book" from Melissa Cardona.
The best one-source place to find patio deck ideas and designs would be to look www.hgtv/patio deck and design ideas. They offer videos and pictures to help you with the project.
The HGTV website has an entire section on deck designs. They have pictures of decks and landscaping for decks and patios. The DIY network also have a number of deck designs the pictures on both sites can give you great ideas.
To find ideas to start building your deck you could first try www.deckplans.com. They have a wide selection of free deck plans along with great tips and ideas on how to build your deck.
Deck ideas can be found at your local building and supply stores or can be found for free online. If you would like to design your own deck visit versadeck.com. Their website will tell you the cost of your deck as you create it.
Deckplans.com have everything you need especially the pictures when it comes to deck plans design ideas. It have all the designs for all types of people.
Eplans website is a great resource to help you with deck patio ideas and designs. The website will also calculate the materials needed to build the deck.
This website, http://www.diynetwork.com/topics/decks/index.html, has a lot of different ideas and pictures that could help you with designing your own deck. They also explain the different types of deck designs that they feature.
Ideas for different designs for backslashes can be found online. HGTV has designs, ideas, and pictures on their website. Pinterest also has some pretty cool ideas as well.