This page contains some of my accumulated wisdom on making conference posters with LaTeX. There is a typical example with its source code. If you want to typset it yourself, you will need the figure and crest which it incorporates.
I also have a simpler example, also with its source code . This includes a second figure which you will need in order to typeset it.
I don't promise that these examples are the best way to do posters with LaTeX. In fact, I am actively looking for a better way to do them. In particular, I am looking for a method that works with pdfLaTeX.