Unfortunately you haven't given us enough details to really give you a detailed answer... However, many principles still exist universally in the development of a UI. One of the trickiest things programmers have to overcome is the temptation to make a programmer friendly UI. By this I mean they tend more often then not to be such that if you're a programmer its easy to use but there aren't enough safe guards to prevent novice users from making mistakes or messing things up royally. Also we tend to lean towards a more lean and mean design over putting in some of the fluff that really adds to the user experience. Some of this might not apply if it will only be technical people accessing it.
Other things to consider: You will need to spend a lot of time thinking about how you will need to access the information. If it won't be you accessing it then you'll need to find out what things would be helpful from the people that will be. Really the point of programming is to make the user's life easier and make it possible for them to do something they couldn't do before. This information will greatly impact how you arrange things and the way you create the workflow for the program's UI.
As for navigation you could have some sort of a menu/sub-menu system? Again with out more details its difficult to give you a more specific answer than that...