The Aces in Tarot represent either the highest or lowest level of achievement. It depends on the reader and on what position the Ace or Aces happen to occupy in a reading.
Personally I am most comfortable interpreting the Aces as the highest level of achievement in any given situation. This is mainly because I tend to see the twos as the first level cards in all the suits.
Just looking at the Aces gives me a feeling of power and full focus. The hand holding the Ace in all four suits seems to be holding on with confidence and full understanding of the cards within it's suit. After walking through the trials, joys and tribulations of the respective suit, this hand represents the entirety of what has been learned and understood.
So, in essence, the Aces represent not only endings but brand new beginnings based upon new knowledge and understanding. In order to really feel the impact of this beautiful and powerful Aces, you need to meditate on each one individually. This would be a wonderful opportunity to share what you are feeling from each Ace in your Tarot journal.
I feel that the Aces are very important cards within the Tarot deck and should never be taken lightly. They are mystical and magical in their meanings and have a lot to offer to both the reader and the client.
The Ace of Cups is an amazing card which indicates strength on an emotional as well as a spiritual level. The dove descending to the chalice with a wafer in it's mouth represents nourishment of the spirit as well as the body and the emotions. The five streams of water flowing out of the chalice symbolize the five senses. And the sea of lotus blossoms below symbolize bringing the knowledge of heaven to earth. So above as below. This is a beautiful card of awakening and awareness that there is more than our five senses understand to be true.
The Ace of Pentacles represents abundance on all levels. Abundance takes many forms, and many of them do not have anything at all to do with money and power. The Ace of Pentacles shows us a beautiful and rich landscape that is growing and blooming. The sun is shining down upon this beautiful garden of greenness and you have the feeling that all is well with the world. This card represents the true meaning of manifestation and abundance. The lessons have been learned and the new "garden" is emerging.
The Ace of Wands indicates creativity and passion on the highest of all levels. The Wand that is being held by the hand in this card is beginning to bloom. And the castle in the distance shows the potential that is held inherent within the thoughts and ideas that are taking root. This is a card of achievement on a creative level. All of the knowledge of the suit of Wands is held within this actively blooming Wand. It is yours for the taking.
And lastly, the Ace of Swords signifies thought and power at the highest level possible. The Sword being held by the hand is clothed in white and is holding a crown and laurels. This represents purity of thought without the ego that is often times involved. The Ace of Swords is a combination of intellect and understanding used to help further the individual as well as society in general. It is a card of altruism and compassion on a intellectual, thought based level.
The Aces are truly wonderful cards to have in a reading. They always represent the highest attainable good within a situation. However, in some cases they can also represent destructive use of power. It is up to the reader to determine which one of these meanings is applicable.