In addition to the above it is important to understand planetary strength. For example, a Mercury retrograde in Virgo is going to pack a lot more punch - energy - than a Mercury retrograde in Pisces because Mercury is exalted in Virgo, it has great strength and talent in Virgo.
Again, it is very important to look at the WHOLE chart, not just the Sun sign, which is why "Sun Sign" astrology is next to the comics in the paper, it is simply not real astrology.
So, knowing where a planet has strength and weakness and how it interacts with other planets is crucial. For example, Hitler and Charlie Chaplin were born on the same day but one has diurnal planets and the other nocturnal which means again the strength of the placement and this time not by sign but by whether the planet is in the top of the chart or the bottom. So, the Sun wants to be diurnal, on the top, the Moon wants to be nocturnal, on the bottom. For more on this, see Robert Hand's translation of "Day and Night Sect Astrology."
The Sun - Exalted in Aries - Rules Leo - Detriment in Aquarius - Fall in Libra
Moon - has strength in which Lilly called "carries" meaning has enough energy to read aspects into the next sign in Horary Astrology in:
Taurus, Cancer, Sagittarius, and Pisces
Moon - Exalted in Taurus - Rules Cancer - Detriment Capricorn - Falls Scorpio
Pluto in Sag has led to the Renaissance, the Age of Enlightenment, and what this will probably be viewed as the Light Age
Pluto in Capricorn will lead to the uncovering of truths about governments and large institutions and corporations. Pluto was last in Cap with the French and American Revolutions.
Uranus is currently debated as strong in Scorpio but as it led to the Third Reich in its previous transit through Pisces and then the Nazis in Aries, this astrologer doesn't think that the planet which rules the "people, the internet, egalitarianisum, electricity" is happy in water. We currently have a group of children born in 1992 who have Uranus in Cap with a stellium and thus far they are pretty amazing although still now only about 15 (it's 2007).
Those I have witnessed closely are exemplifying kindness, strength, an unbelievable brilliance blowing IQ tests away, humility, generosity and a deep understanding of mankind. So, there may be some reason, if the rest of the generation of Uranus's transit through Capricorn also exhibits strength to look to this placement. And, historical research would need to be done on this placement.