I need to set ALT Tag on my WordPress site but i am enable to find image on it's penal. I am also looking onpage optimization technique for word press site.
When you upload an image there is an "Edit Alternate Text" box, or you can do it in HTML using <img src="url" alt="alt text">
when u are going to upload images from Media library the dashboard panel will give You Title,Alternate Description text and other information where u can add Alt tag and for On page Optimization ALL IN SEO will hep u lots all others techniques here u can get in this forum http://forums.digitalpoint.com/showthread.php?t=2064523
Fill in the 'alternative text' box when you upload through the media uploader tool, or click on the HTML when you have your image in there and add ALT=" " to the image string.
when you upload a picture there is an option, type in the text you want to appear in the alt tag text label.
It's easy to add Alt tags as you load each image - as already explained. If you already have pictures on a site without tags, unfortunately you need to go through them one by one to add tags - but there are plugins such as WP Pic Tagger that help in this process
After you have successfully uploaded an image, It gives you the chance to write image's 'title', 'alternate text' etc. You can easily write your required alternate text there.