ASPE offers on-line classes in estimating.
Taking the online intro course through the national ASPE introduced me to several fundamental aspects of an estimate. The most rewarding part for me was going through the different levels of an estimate from start to finish. This allowed me to gain an understanding of the in-depth preparation and purpose of the estimate leading up to bid day. I would certainly recommend this course as a starting point for someone who is interested in becoming an estimator.
Ron Semel and Mark Pitts conduct an Estimating Workshop at Highland Springs Technical Center November 1st 2012
If you would like an Estimating Workshop at your school, contact Ron Semel at firstname.lastname@example.org