Are there agents at each train station in Switzerland? Even the small ones? We will be doing quite a bit of traveling, and would like to know that someone would be there to advise us along the way.
I would think so, but you never know. Download the SBB app just in case.
No. The larger train stations are manned during normal business hours, but the smaller ones usually just have a ticket machine. sbb.ch will provide you with schedules, and you can purchase tickets in numerous ways.
I had SBB "greeters" approach me and help my group at the Zurich and Geneva's Cornavin stations to help us get the right tickets for our journey. I have never encountered more helpful people at the itourist offices at all the bigger train stations (Bern, Basel, Luzern, Lucerne) than I had in Switzerland. They had great info, and were helpful with train questions as well.
I haven't been to Switzerland recently, but I think surely the ticket-vending machines there (like those in Italy and Spain) allow you to select English as the language of display. That will generally be all the help you need.
Pocaj, no. Most of the smaller stations (I guess > 60%) are totally unmanned, ticket machines only. The larger ones have people selling tickets, and info desks where you can go and ask, but they don't have people walking around looking for lost tourists :-)
On the larger stations there are staff on the platforms dealing with the trains. These will always answer questions if they are not busy, but may not speak English.
Stations in tourist orientated places are more likely to have ticket sellers and info booths than are stations of the same size in other areas, as tourists are less familiar with the system and with using ticket machines. And tourist stations may well have a tourist office for general information.
What sort of "advice" would you be looking for? Finding a train is easy, all stations have departure boards and screens listing all departures for the next 30-60 minutes, and their platform numbers.
Example here from Luzern: http://i751.photobucket.com/albums/xx157/dolphinair/Interlaken/ZB_start_TR.jpg
You then go to the platform, and there are "next train" indicators above you. Example here from Basel SBB platform 10: http://www.mccrow.org.uk/switzerland/BaselDepBoard.jpg
You can look up train times, and platform numbers, before you get to the station on the SBB website: http://www.sbb.ch/en/home.html