That's some information that took me some time to gather.
Feel free to include it as it is or correct it :-)
No need to mention me in the commit.
diff --git a/wiki/src/build.mdwn b/wiki/src/build.mdwn
index 88253be..6a453b9 100644
--- a/wiki/src/build.mdwn
+++ b/wiki/src/build.mdwn
@@ -39,3 +39,28 @@ manpage for details.
You can then use the standard live-build commands as root to build
the image (`lb build`) and to cleanup the build directory (`lb
clean`).
+
+Build with alternative debian mirror
+------------------------------------
+
+Visit config/chroot_sources and adjust the files found there according to
+your mirror of choice.
+
+Then configure the bootstrapping process (read lb_config(1) to understand the
+options):
+
+ lb config \
+ --archive-areas "main contrib non-free" \
+ --mirror-bootstrap http://localhost/debian \
+ --mirror-chroot-security http://localhost/debian \
+ --apt-secure false \
+ --volatile false \
+ --security false \
+ --distribution lenny
+
+and finally
+
+ lb build
+
+Some files that are not coming from debian will still be downloaded from
+elsewhere.
