Should I put alt tags for every piece of artwork on the site? Or should i just concentrate on actual images? And if the answer is yes for every piece of art...how will this help in the SERP's?
Know this! ALT tags are an alternative method to tell users with primitive browsers or browser capabilities disabled. These ALT tags tell search engines "what this image is about". It comes under best practices to optimize (not over doing) the ALT tags. Thank you
All actual images should have alt tags. In your case, you should have alt tags for every car image. For accessibility reasons, it is a good idea to have alt text for any other major graphics on your sites. This can help with getting extra image search engine traffic. That alt text also reinforces what your pages are about. Alt text is a must for any images used as links. It may not help putting alt text in smaller design element graphics.
As a rule of thumb we use the alt tag on all images. If they are small in size like 'spacers', we leave it blank. But for any real image, it is SEOed with the correct string. Also, any image greater thant ~40 px by 40 px should be SEOed. But none of the Alt tag "strings" should be the same. Keep them on SEO topic but vary them as much as you can.
Alt tags are designed to show text in place of images for people who are browsing with text browsers or in the event of a browser incompatibility. So label your images that would look out of place if they were to fail to load. There is no reasonable reason to label every image in your design that is part of the design itself. Each relevant image that is useful to a viewer can benefit from a descriptive alt tag. A few words at most that accurately describe the content.
as search engine can not crawl image or flash content, thats why they recommend us to provide image description which will help visitors and crawler to get some idea about relevancy of images with your website. To provide small and description alt tag will help you to increase content for your website that will help a bit to get higher search engine rankings.
alt tags are very important when your posts are mostly of images - but othersise its not important .Most of the celebrity blogs concentrate on this - and yeah if you want to rank high on google image search , you must definitely concentrate on alt tags. One of my celebrity blogs was receiving 400 visitors everday from image search . so never ever underestimate it .