Ensure the financials to see if they are making more money than they are spending and if their operational plan makes sense. Strong business plan and results. The trouble for most people is that there is lot information available and it’s difficult to make a decision. You should buy based on charts, based on ground rules, based on insight. Sometimes, it’s a amalgamation of all three.  When a penny stock newsletter or service reviews a company, and analyses all the details, it is a fine to read that report and settle on if the company fits with your trading goals.
   
What is the best stock to invest in? The answer varies daily, and mostly, it relies on what level of risk you can undertake. There are a lot of publicly traded companies. Therefore it is your first job to know yourself that what kind of investment you are interested in. Thus you find the right trading stock companies.