I have read somewhere that Google may penalize you if you have little content on your website. I wonder how many articles should I have on my Wordpress blog at minimum to stay safe? Let's say one my article has around 500 words. Currently I have 3 articles on my WP blog. Is that enough? Also, I've made only the latest one article to show on the homepage - Can this harm my website?
In my opinion you should have at least 10 articles if you want to call it a BLOG anything less than that looks like a spammy site.
Ya, Add quality content at least once a week, 500 - 1000 words would be best. Just keep adding content. Google will like your site a lot more.
I've read a guide from someone who is doing extremely well in ranking hundreds of his websites recently, and he insists in writing (or having others write) between 750 to 1,000 words or even more for each article. Google seems to like these more and more ever since the EMD update. The logic he used was that by now, Google must already know that blogs or websites with 500 word articles are a dime a dozen and are usually spammy sites. So having longer articles makes you safer from google's eyes.
400-500 words must be in one article. And it will be more beneficial if you update your site regularly.
You shouldn't necessarily focus on posting a lot of content, but posting original content regularly. Be consistent and publish new articles a few times a week. Build links to your pages and promote your content on social media sites, blogs, forums, etc.
500 words article is enough but you can use more than it. At your blog post in every 2 days a article but in blog you can post 400 words article that will be enough.