Last night at the Boston MySQL User Group I presented on how to get a consistent snapshot to build a slave, how to use mk-table-checksum to check for differences between masters and slaves on an ongoing basis, and how to use tools such as mk-table-sync and mysqldump to sync the data if there are any discrepancies.
The slides are online at http://technocation.org/files/doc/slave_sync.pdf.
The video can be watched on youtube at http://www.youtube.com/watch?v=Un0wqYKmbWY or directly in your browser with the embedded player below: