1. All in one SEO :- This is the very first plugin that you need to install when you start you wordpress blog. This plugins handles all the SEO for your blog and keep your content search engine optimized . You can enter keywords , description and meta tags for each of your posts using this plugin.
2. MaxBlogPress Ninja Affiliate :- This is the best ever plugin designed for those who want to make a fortune in affiliate marketing with their wordpress blog. This plugin automatically converts keywords into affiliate links thus giving you complete freedom from the heck of inserting affiliate links here and there in your blog. Also you can keep track of your affiliate links.
3. Awesome ads :- This plugin handles all the Google Adsense and Chitika ads on your blog. You can easily customize everything related to your ads using this plugin.
4. Akismet spam killer :- This plugin takes care of all the spam that you might receive in the form of comments. Generally , you will receive 100s of spam comments daily once your blog gets going. Moderating such a huge amount daily is a tough task. Akismet solves this problem by distinguishing spam with almost 100% success rate.
5. Sociable wordpress3 :- This plugins integrates social media into your posts, pages, categories or almost anywhere you want . This plugin has over 100 social media sites to share you content. Your visitors can easily share your content if you use this plugin.
6. FeedBurner Feedsmith :- This plugin extends and redirects all your wordpress feeds to feedburner feed which is more profitable and can be monetized easily.
With these must have plugins , you can also use:
1.Subscribe to comments
2.Follow my blog post