I'm looking for a place to send my 240+ SEO students to learn and ask questions?
Will Pro Webmasters help them?
Yes. SEO is an on-topic subject here and is, in fact, the most popular topic here.
But keep in mind that all questions, even from students, must follow the site's rules. As SEO questions are frequently asked, this means most questions already have an answer. I recommend that you encourage your students to use the search functionality of this site before asking a question as most questions will already have been answered.
I also recommend you have them take the tour so they have a good understanding of how the site works.
Your students are welcome to ask on-topic questions here. Our community will do our best to support them.
I'd ask that you try not to overwhelm the site. Please don't ask all your students to post questions on the same day (or even in the same week). This site typically only gets a few hundred questions each month. Our community has the capacity to answer more than that, but if too many questions get asked too quickly, many of them are likely to go unanswered.