The first starship Enterprise, its crew and missions. Its captain is Johnathon Archer. He's kind of a mix of captains Kirk and Picard. Ready to fight but knows that diplomacy is also important. The crew is comprised of sub commander T-Pol, a female vulcan officer, Commander Charles "Trip" Tucker, Lt Malcolm Reed, Dr Phlox, and ensigns Hoshi Sato and Travis Mayweather.
Enterprise is Earth's first warp 5 space vessel. Earth is eager to explore space and make contact with new species. Standing in the way are the Vulcans. The Vulcans feel that Earth is not yet ready for this mission, they feel that humans are still "too primitive". But Archer and Starfleet are determined to make this mission work.
Along the way they deal with established Star Trek beings, the Andorians, Klingons, and Tellartes. They make contact with many new species, including the Xindi (major players in s3) and the Suliban. We also see the appearance of the Borg, who in the past made first contact with TNG's Enterprise. Captain Archer also has experiences with time travel. A Starfleet officer from the future contacts him on occasion regarding Enterprises impact on history.
It's kind of weird to see an early version of of the Star Trek universe with more advanced technology that that of the future. Of course you have to account for the fact that the original series was produced in the 60's. But still, it's still a little strange. I didn't start watching Enterprise until it was canceled and being shown in reruns. The special effects are good. I liked the storylines. One of the best was the explanation of why the Klingons ridges are missing during the original series and their reappearance in TNG. There was a virus that affected the Klingon race and it erased the ridges. T'Pol is an interesting character. She's Vulcan and they pride themselves on being able to supresss their emotions. T'Pol however, was very emotional, for a Vulcan that is. She fell in love with Trip and was very attached to him. Trip was my favorite character. The relationship between him and T'Pol was that of love/hate. He distrusted all Vulcans but respected her and he turn fell for her as well. In fact, he made his feelings for her known before she admitted her feelings for him. I was very sad when he was killed off in the series finale. :(
Dr Phlox is an alien called a Denobulan. His race's marital practices include polygamy. Every man and woman have three spouses each. Phlox is eccentric and amusing. The armory officer is Lt Malcolm Reed. His family has made the navy a career for generations and enterprise is just a different kind of ship. Hoshi Sato is the linguist specialist and communications officer. Archer hand picked her for this mission because of her uncanny ability to decifer and translate all kinds of languages. Travis Mayweather is the helmsman. A big part of the storyline of the series is the progression of tolerance of alien species by humans. At first, earth was reluctant to accept their new friends and allies. It took a lot of work to establish trust. Eventually, during the series finale, the Federation charter is signed. Captain Archer was it's architect hundreds of species are united in friendship and peace.