I am trying to install just pdfLaTeX without the rest of the stuff that comes in packages such as MacTeX. All I want to be able to do is convert LaTeX source files into pdf's. I downloaded the pdfTeX package from http://www.tug.org/applications/pdftex/ and followed the directions to install it, but I couldn't do it properly. Can I create pdf files out of LaTeX source files with just pdfLaTeX? Also how do I install it?
The binary (pdfTeX) alone is not enough to compile a LaTeX document: it alone is not even enough for a plain TeX document. TeX needs for example a format file, fonts, and a way to find these. If you want something smaller than MacTeX, BasicTeX is probably the place to look. It is a 'minimised' version of the same system, so can be expanded as needed (say it turns out you need one or two more packages than BasicTeX supplies). Another alternative is KerTeX, although this means a more restricted set of binaries (no pdfTeX as KerTeX's licensing approach means no GPL software).