Twitter may be a good medium to bring traffic to your site by your followers. You may be writing personal tweets there, but always updating new posts may be challenging task especially when there are more than 3-4 authors for your site.
Is it a Good Practice?
Though it is not considered a good practice to use programs to automatically tweet your new post, as it lacks creativity, and ultimately looses user interests. But it may help you for a time frame when you know that coming days may have a busy schedule, so that you won't be able to share your articles manually.
I am here discussing two best services to smoothly carrying out the task.
#1 Deliver It
dlvr.it can auto-publish your content to social networks including Twitter, Facebook, LinkedIn, MySpace, Status.net etc. One nice thing is they can alert you in case any problem occurs in reading your feed, or publishing it.
- They check for article updates every 15 minutes, but if your feed is PuSH enabled, it'll reach your followers in real-time.
- It can automatically add contextually relevant HashTags to tweets. This will make it search-friendly.
- Choose custom URL shortener service
- Keeps track of your followers.
- API for more customized control
#2 Twitter Feed
twitterfeed.com is a service from popular URL shortener Bitly. Not only Twitter, but the site allows you to update feeds even on Facebook fan page and LinkedIn. The real time stats feature of the service will surely help you to understand user engagement.
It offers nearly same features as dlvr.it, but has some difference also. Be sure to check their knowledge base articles to make best use of them. You will miss API facility here.
Besides these two, there are a number of other similar services available where you don't have to pay a single penny. Experiment with them, may be you found something suitable as per your need.
 as per my opinion.