The only thing with which I differ is Rita's leaving her external HDD as a single partition.
In one of her other threads I suggested that since it's so big, 1 TB compared to her 120 GB internal SSD, she make 5 x 100 GB partitions and 1 x 500 GB partition.
That will leave her space to potentially back up five different OSs in the small partitions plus run Time Machine or do whatever else comes up in the big one.
Someday.
