I too would like to welcome you to the forum.
The advice David gave you, in line with your own thoughts, is perfectly true and sound. Beware however that most mistakes in navigation were made when plotting a position on a chart. Nowadays chart plotters have made the making of such mistakes a rare occurance. Just be careful when plotting!
FYI I have used a GARMIN 72 for quite a long time and never had the slightest problem with it. It is run from the boat's 12v system and connected to a laptop (running Navmaster and Admiralty charts). The set up has worked perfectly but I am now considering buying a plotter. The new Garmin stuff looks very good.