One difference between public companies and private companies is that public companies have disclosure obligations. So investors can review the publicly disclosed information to determine where there is a suitable investment target. In Canada public company disclosure documents are available at www.sedar.com, including annual and quarterly financial statements, press releases, prospectuses and other major disclosure documents, material contracts, annual information forms (for TSX companies), etc. Further, the insider information of the public company is also publicly filed, available at www.sedi.ca. Insiders of public companies include its directors, officers and shareholders holding 10% or more. Insiders are required to report the increases and decreases they hold in the public company in shares, options, etc.
Whether you are looking for a public or private investment target, you can always use intermediaries such as brokers or consulting firms to assist in your search. However, intermediaries will generally charge a fee. Also, if the intermediary is in the business of trading or advising, they will need the appropriate securities dealer/advisor registration.