Guest blogging is better as you can target other websites in your niche that. You will be getting relevant backlinks to your site. Plus Google will love it too.

If you want to get started I would recommend this site:

Login Form - My Blog Guest

I see this question asked a lot so I thought I would write a quick article about it on my blog to answer the question more thoroughly you can check it out here:

Is Article Directory Submission Still Relevant Today?

Hope this helps.

If you want to get direct traffic from article directories, you need to write plenty of articles then submit them to article directories that have high traffic. Let say around new 500 articles per month.

Looking for article directories which ranked below 10,000 in Alexa.com. And follow guidelines for staying at article directories.

EzineArticles is the king of article directories, it is a must.

Yes, article submissions are still in business. But choose site carefully.Choose only those which have good page rank and which moderate your content.

I would like to thank you all guys. Thanks a lot

Article directory is still a good source of traffic but according to several studies i found that article directory submission doesn't worth more now days. Read the article below:
Ezine Articles & Press Releases Supplied As Bad Backlink Examples in WMT

I agree with "the brewer". A good alternative of article directory submission is guest posting. Guest blogging isn't good source of back-link but also provide qualified traffic to your website.

The other best approaches of content marketing are Web 2.0, slide share, PPT, PDF, e-books etc.