i don't know anything about automatically interfacing between gps devices and websites (it may be quite easy but i suspect not) but given you say you're not serious programmer why make it so hard? it seems the interface part could be done, as someone suggested above, manually; have a page which is password protected (using apache's standard thing so you don't have to create it your self) page which allows the people to make entries, consisting of, time, longitude and lattitude, for that data to get inserted into a database. or, even simpler, why don't they just email you this info and you plug it into the site yourself? which ever way, then once the data is on the site have code for google maps served up appropriately, the server side code which generates the code for the google maps pulling the relevant info (time for the label, and long+lat for the actual position) from the database which was either put there by you or the people themselves. it's the serverside code generation which makes use of the long+lat data approparetely thus serving up google maps code which'll display what you want to people -- it's *that* that's the important tricky (but not as tricky i suspect as interfacing automatically) part which you need to get sorted. so concentrate on that. so the question becomes, how do i generate code for a google map which takes a varying number of multiple label,long,lat bits series of data from a database to show people the path/route? if you've already got that sorted ignore what i'm saying. that's the essential part. if and when you get that sorted then looking into automating/hooking it up directly with gps. that's my advice.
so there's two parts. getting the info from gps to website. and the serverside code (which makes use of info from gps) to generate google maps code. the first part, if people are willing to do a tiny bit of ongoing work to make it work, is a doddle (e.g. email, then you put it onto the website). get the second part sorted.