Facebook, LinkedIn and Twitter Plugins

Sorry if this is redundant. Is there a plugin that will take my blog posts on our website and put them into our Facebook page? Also, is there a plugin for putting a link on our site that will enable a visitor at our site to go to our LinkedIn, Facebook, Twitter, etc. profiles? Lastly, is there a plugin that will search twitter for tweets about a company or a blog post and download that tweet to our blogs side bar?