God how I envy you with all that great countryside yet to discover.
Follow Clodhopper's advice and you'll not go far wrong, just hope you get decent weather to do it justice. The western seaboard of Scotland is a fantastic place. Pay special heed to Clodhopper's remarks about Glencoe and the Ben (Geln Etive is really good too).
A word of warning though - it will probably be the start of a lifelong addiction.