NAVIONICS

www.google.com.au/search?q=Navionics++simbols&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=sb&gfe_rd=cr&ei=0wF_U8-FDunC8geMqICgCA#channel=sb&q=Navionics+symbols&rls=org.mozilla:en-US:official&spell=1 < quick google

www.mytopo.com:443/maps/
A. Navionics charts include an "Xplain" feature. This is a plain-language description that, with just a click of your cursor, deciphers confusing navigational symbols into plain-languge everyone can understand. To find out how to access object information, please consult your unit's User's Manual.

As far as I am aware the lap top version of Navionics is not interface able with an external GPS device such as a puck GPS receiver.

It may have changed but if the device (smart phone, tablet or PC) does not have a built in GPS chip you can only view the maps but not actually use them to get a position or for actual navigation.

Check up before you check out.