Compensation is a "hush-hush" topic. Recruiters don't want to address it specifically and it changes from yr to yr based on various factors. Do they tell you beforehand? Don't remember any employer that did that. You find it out in your offer letter (for internship only if it is internship offer, and FT salary is revealed in FT job offer letter)
A lot of companies (big ones with specific program in place, like a pipeline program for developing talent) do create summer internship programs with the idea of evaluating talent for FT job offers but surprising number of companies don't. Some companies have a need to bring in new talent every year because x number of people leave but a lot of companies have stable environment where they can't forecast accurately on whether they will have openings or not (by the time the summer internship ends, etc)
Can you get an idea of FT salary info, etc? Sure. It's easy for jobs in MC and IB, etc because salaries are competitive and similar from yr to yr. You can always ask 2nd yr students who did a stint at a specific company yr before.