Any home improvement store should have a deck or patio section. I recommend looking at Ikea, Home Depot, Lowes, or a different improvement store near your home. From there, you should be able to find an assistant there that can help you design the patio/deck that would fit your needs.
A great site I found to find browse deck and patio models is merchantcircle.com. Here they have multiple lists of patio and deck merchants in Philadelphia who will help you browse patio and deck models
You can find free deck and patio designs online at freedeckplans. They even tell you how much the material will be and measures the deck as well and prices it as well
You can find patio furniture for any patio or deck at Sears. There will be many sets to chose from for any deck or patio. You may also want to try Wal-Mart.
You can buy a deck patio lighting in this site online www.lightinguniverse.com/Patio this is the largest patio lighting in the internet and www.partylights.com/, you can find some of online deals there.
You can check this website: www.deckplans.com/free-deck-plans and look for their patio deck plans. You can also look for www.deckplans.com. I hope you will find a deckplan suitable for you.
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.
Consult your local deck and patio contractors. Also check Angies list to find out what people have to say about those contractors and to compare prices.
Eplans website is a great resource to help you with deck patio designs for your backyard. The website will also calculate the materials needed to build the deck.
You can measure your patio deck with a tape measure.
You can find outdoor patio deck plans anywhere on the internet. I'll give you a couple of websites to save you the time you would waste otherwise: www.deckplans.com/ www.virginiadeckdesigns.com/ www.deckandpatio.com/
You can find out where to buy a book about patio and deck plans and read information to compare prices on the internet or go to your local shops and en quire about it there.
The internet is an amazing resource and has multiple options for patio deck designs. Some of the sites you may want to look at are the HGTV site as well as DIY and Youtube.