When you have run out of ideas but still need to have another 30 articles written and submitted by the end of the week then you will eventually turn to plr articles. There are many suppliers of plr article packages that range from the excellent to the plain dreadful. I have a number of plr sources that I have found over the years. Once you have your plr content to hand then you need to look at how to use and rewrite plr articles content to get the best result for your purchase.
You must in the first place acknowledge that these plr articles are cheap and not ready to go. they need some work. The reason that I point this out is that you can afford to be a bit choosy with them. I recently bought 120 articles in the credit card niche for $10. I recognise that only half will suit my needs. I do not feel I have wasted my money. I usually find that not all the purchased plr content is too my liking but at least half will be good enough. I am a bit choosy about what I include in my articles. Do not think of this as an issue. You will never like every supplied article you receive.
The second point is to make sure you have your own set of keywords ready. I never use the ones supplied because they are sometimes out of date. I will already have done a few hours looking into the keywords I am going to use before starting a writing spree.
Finally you need to know that you must rewrite these articles. Do not submit them without changing them by a minimum of 25%. In fact my minimum is 50%. You must ensure that your articles is unique.
To know how to use and rewrite plr articles content you can get a free tutorial on article writing by going to the mega article website. This site will help beginners who do not know the ins and outs of writing a really good article.