If you are looking to start and end your business on the web then you can skip the meat and potatoes.
If you've been at it for 14 years, chances are you have some solid business experience and probably better industry related experience. Build off of that. Use your past experiences to help build future experiences.
300-500 word articles are subjective. You'll have to do some recon and check your competitors sites and find gaps in their content and fill those gaps on your own site. Check the data to see how much retention you get for a 500 word article vs a 300 word article. You may find that you can achieve the same results with less words. Write for your visitors.
Some basic tips being that you likely didn't read through the million and two other posts that discuss it would be to use the google adwords keyword tool. It's free. Enter the term in quotes and find terms that have less then 90,000 results and build from there. Enter a term and search for it in google and look at the suggestions google makes and write content around those terms.
Or you can try reading this thread where fathom discusses a possible method you may want to tackle.
If you don't have the time to write the content yourself, hire someone who can. If you don't want to hire someone, then spend the time to do it yourself. You can't have your cake and eat it too unfortunately. Pick two, time, money or results?
"Give a man a fish and you feed him for a day. Teach a man to fish and you feed him for a lifetime." Chinese Proverb