You need a fast, steady connection. ISDN access is preferred in part because of the stability and consistency of download speeds. You need to estimate the cost of this time yourself. I find it is most efficient to browse the entire site first, downloading files, saving or printing out assignments or comments I want to remember. On later visits, I ask to see the assignments and comments in date order and look at the ones posted since I was last there.
Many people find it very frustrating to type more than a few words on-line at one time.
A fellow DE instructor Valerie Mock has set out a useful strategy for reading conference material off-line . You may need to use your ID and password two or three times during a session. Users with slower computers will find this on-line process slow. At busy times, the server is slow even for those with faster processors. When this happens, be prepared to log off and come back at a different time.