Important websites for HD/HQ pictures and other graphics.
HOT!:Mad over Graphics forum - Improve your graphics here!
Stock Photography, Royalty-Free Photos, Videos & Music | Getty Images UK - Yes the pictures have watermarks but try resizing it, it might just work for Graphics and it will not be illegal to do so.
Zimbio - Entertainment News, Celebrity News, Celebrity Photos & Videos - Every one here knows about this but to those who don't you can get really HD/HQ pictures, IT MIGHT UPDATE LATE.
http://www.flickr.com/ - A very decent website for good pictures.
Chris Creamer's Sports Logos Page - SportsLogos.Net - For logo edits.
Photo and image hosting, free photo galleries, photo editing - Not the best but you can get some great pictures from here.
deviantART: where ART meets application! - One of the best websites to get good images/ textures/effects/tutorials.
Live cricket scores, commentary, match coverage | Cricket news, statistics | ESPN Cricinfo - For HD Cricket pictures.
Football | Home | ESPN.co.uk - For HD Football pictures.
Live rugby 2014 | Aviva Premiership 2014 | Rugby Union fixtures and news | ESPN scrum.com - For HD Rugby pictures.
F1 2014 | Live Formula 1 Grand Prix news | ESPN.co.uk - For HD F1 pictures|You can get some awesome stock from this.
Boxing | Home | ESPN.co.uk - For HD Boxing pictures.
Golf | Home | ESPN.co.uk - For HD Golf pictures.
Tennis | Home | ESPN.co.uk - For HD Tennis pictures.
http://uk.eurosport.yahoo.com/ - Similar to ESPN but you may hit different pictures.
http://www.footballpicturehd.com - The name says it all, but the website takes time to add newer stock images.
Renders
Mukesh's Renders - One of the few few threads to have both Cricket and Football renders and that to in HD! Takes requests and does the renders cleanly.
Simon's Renders - A very clean thread with great clean hd renders which mostly includes football and cricket renders. (Update quite regularly) - Thanks for Simon for allowing me use this for my second post of guide.)
Meet's Renders - For the best hd Cricket renders.(Credit goes to Meet for allowing me to use his thread as a part of the link here.)
? Football Renders | The Best Source For Football Renders! - For HD Football renders.
FootyRenders | Your Source for Football Renders! - A great website for clean HD Football renders.
*Lets get one thing straight, I am not the owner of any of these sites. 
Credit goes to the people who put their hard work to put this great pictures up for us to use.*
