Increasing My blog earnings

Yeah you are rich content articles can attract more visitors, Most of the bloggers run out of the topic to post. If you wanted to post other people's artcles then its ok if you give the author credited, Always put the website or articles taken by writing source---website or articles ... But I recommend you to collect 4-5 articles of your interest and combine them to make new articles and post it on your blog, this is benefit you more than the earlier because search engine likes fresh contents. Most probably you can visit. http://ezinearticles.com/ http://www.goarticles.com http://www.articlecity.com/ http://articlehub.com http://isnare.com Collect some useful content and remake them but don't copy paste the entire content. Make by your own words. I hope this will help you out.

well you can write about anything that is popular and do a search to find articles which are free to use 1 poster here has some links to free article directories maybe you could add some photos and videos and write on a few different subject and see which ones get more visitors

While you are always better off having your own original content on your blog you can freely use content from a variety of article directories etc to supplement your own content. People submit to these sites and give you permission to use their articles on your sites - providing you follow the terms set out - placing their names and links etc. If you're interested you may find some more information and a couple of article directories here http://www.squidoo.com/article-writing-marketing/

I really don't think it's legal to post other people's articles on your blog. Unless you plan to give the other person credit for it on your blog, then I guess it's ok. You really should try to come up with your own content though. Some things you can do is search news sites and write your opinions on various articles on there and things like that. If all you are planning to do is copy and paste articles though, I don't think your blogs will become very popular.