Well, X-Com: The Unknown Menace is the first book I ever finished in English. And I'm from Portugal, in case you're wondering.
The Unknown Menace, Eulogy, Abyssal and Destined Alliance are based on the X-Com universe, where the aliens and UFOs exist and they are not friendly at all.
They are based on the computer games X-Com: UFO Defense, set at the end of the millenium; Terror From The Deep, regarding the second alien war on the 2040's; and Alliance, a game that was never finished and that was set on the 2060's. "The Unknown Menace" deals with with the First Alien War (1998-2003), "Eulogy" is a short story set after the war, in 2009, "Abyssal" with the Second Alien War (2040-2046), and "Destined Alliance" will become a part of yet another story, which starts in the 2060s.
Now I'm concentrating on Abyssal, which is set underwater and will carry on the story and some of the characters from the Unknown Menace. In case you want to know more about the story of X-Com I recommend that you read the Timeline that is on this site. I'm trying to stick to it as much as possible.
What are my main influences on my writing? Well, I'll give a list of what I enjoy reading, not only on sci-fi: the Classical Battletech novels; the Aliens books; Robert Henlein and Isaac Asimov; Frank Herbert's Dune series; Phillip K. Dick. Finally I used to read a lot of Tom Clancy's earlier novels (Hunt For Red October, Red Storm Rising, etc.) and other military fiction.
If you want to see other UFO stuff I am doing besides fanfic please check http://area51.xcomufo.com/index.html

Also, there's a forum at this site where you can discuss the stories. Just click above where it says: My Forums.