Re: Shifting...(warning I am famous for, ask me what time it is, and I tell you how to build a watch)

Your Dolce has 50/34 up front for the chain rings and 11-32 on the 8 speed rear cassette.
The 8 speed cassette has this gear combination: 11-13-15-18-21-24-28-32

When you are in the big chain ring (50) your best combinations will be:
50x11, 50x12, 50x15, 50x18, 50x21 & 50x24
This gives you 6 gear combinations. Don't use 50x28 or 50x32 this is called "cross chaining".
It is hard on your gears, and will wear them out. Noisy too.
50x11, 50x12, and 50x15 are your gears for sprinting on flats and bombing down a false flat gradual descent.

When you are in the small chain ring (34) your best combinations will be:
34x15, 34x18, & 34x21, 34x24, 34x28, & 34x32
This gives you 6 gear combinations. Don't use 34x13 or 34x11 this is, again, called "cross chaining".
It is hard on your gears, and will wear them out. Noisy too.
34x28 and 34x32 are your climbing gears and will really save your knees.
If the grade is not to steep or too long you might carry speed up such a bump in 34x24, leaving you 2 easier gears if it gets tougher.

Early in a ride I spend most of my time in 34x21 or 34x24 until I am warmed up, even on flat roads.
Once warmed up the same flat road might find me in 50x21 for a nice cruising speed.
I climb mostly in 34x32 or 34x28. I like my knees to much for mashing up hills.
Spin to win is the philosophy I follow. Lower (easier) gear combinations and faster pedaling (called high cadence)
Pedal speed translates into ground speed when you spin.