As Derek says it is it's not easy to self build. Do you know just what you want as their are options that do not require foundations so it can be achieved a little easier. Below is three links that will give you an insite to Wooden houses as the Algarve link shows, Timber frame house and this link shows just how the various parts are made, the last link is to the Timber Frame association in the UK. All links give details of the different aspects to Wooden House or Timber Frame houses. I have been told of a new system being developed that has all the benefits of Timber Frame but it can just be lifted by crane onto site and as no foundations are requires then it's classed as portable so i am told no planning is required.
It's not easy just building a wooden house but i hope the links are of help
Good luck but first find out what you want and what you expect to be able to get from you new home to be.
Peter the 666 man
Timber Homes Algarve
Timber Engineering Europe
List of Members - UK Timber Frame Association