in the SEO marketing or SEO “designing” (and what’s the correct term for the occupation?) industry?
I am about to finish an internship at a TV station where they had me to create metadata for the Youtube clips of TV productions.
If you’ll be doing solely SEO work, expect to be spending much of your time doing keyword research!
I would also be very interested in the day-to-day tasks of various entry-level positions? especially HTML/CSS developer.
I guess it depends on your skills. Probably the less complicated sites, the small ones, things like that. That’s at a guess 
Probably building backlinks, keyword research, basic stuff that you can be explained and then do, no real hard work or thinking, probably very similar work to somebody doing a 9-5 data entry job.