As mentioned in Stefan's answer to How to customize headers and footers?, fancyhdr is the classical package to customize headers/footers. However, recently I've been using the titlesec package to define page styles, and I've found it really useful and as powerful as fancyhdr, so here's a little example achieving the desired result with titlesec:
\documentclass{report}
\usepackage[pagestyles]{titlesec}
\usepackage{url}
\usepackage{lipsum}% just to generate some filler text
\newcommand*\defaulturl{\url{www.some-url.com}}
\newcommand*\defaulttitle{Some Title}
\newpagestyle{mystyle}{
\sethead{\defaulttitle}{}{\chaptertitle}\headrule
\setfoot{\defaulturl}{}{\thepage}\footrule
}
\pagestyle{mystyle}
\begin{document}
\chapter{Test chapter}
\lipsum[1-40]
\end{document}