How to allow visitors to post questions on the homepage of a wordpress blog.

I believe you can configure Gravity Forms to do this. Basically, they'll fill out the form (ask a question) and when they hit submit it will trigger Wordpress to "post" it.

I would probably do this with a plug-in. Just search plug-ins for "FAQ", and adapt the one that looks nicest. Some of them come with shortcodes, but I'd look for one that has a whole section or page to itself, and then set the blog to use that page as the homepage, which you can do under the "Reading" section of the Settings.

I would like to thank the both of you for your suggestions. I thought I leave a message in case any other people had question about the same issue. I'm in the process of testing them out, but I think the "FAQ" plugins will be perfect for my site. Thank you Karen, the "FAQ" plugin is a great suggestion.

Use a plugin called "User Submitted Posts" or something like that. Search on WordPress.org/extend/plugins

There are a few plugins... just go through them and see if any serves your goals:
WordPress › Search for faq « WordPress Plugins

Thank you all for all your suggestions, even though I haven't found the solution to my problem just yet, I have come across some very interesting plugins thanks to all of you.

The faq plugins are really nice and I'm going to incorporate one to another one of my blog, but for a different purpose. I've checked 5 different faq plugins and while some of them feature a very nice way to do a single q&a session, it doesn't allow you to have continued strings of conversations.

I'm looking into using the "user submitted post" and it looks really nice as well, but it also comes up short on the ability to continue a q&a session. I've come across a nice q&a plugin, but it has a ridiculous price tag. It's $200+ for one year support and update. You can get a professional q&a theme for less than $40, so the price tag for that plugin seemed a little steep to me.

I found a couple of q&a plugins that look pretty interesting, I'll test them out and make another update on it once I figure them out. Thanks again everyone.

You could try the AskIt theme from Elegant Themes

It does exactly what you need without the use of plugins and for $39 you get access to all of his themes for an entire year.

P.S: That's not an affiliate link

Thanks zulfnore, I found the theme you suggested and another nice one from forest theme already, but I rather not change themes if I don't have to. The atahualpa theme is highly customizable and you get top notch support. I slowly improved the design of my site for the past 2 years using the same theme and I don't see myself changing the theme anytime soon for any other reason than it ceasing support.

Anyways, I found a plugin called "ucan post" and its similar to what xtrapunch suggested, but only better . I'm going to set it up so that only registered users can post and that way I get to increase subscribers as well.

I'm still testing it, but what I have done is to use the shortcode on a post instead of using it on a page. I "sticky" the post and that way I have series of questions following the question submit form and as well as my own posts. I figure I could use the comment feature to answer the questions and the op can use the comment feature to follow up on an answer if they choose to.

Btw, using the shortcode on a post instead of a page you end up with a not so attractive post form. So if you want a nice and colorful WYSWYG text editor, then I suggest you use the shortcode on a page. I'm not so sure that anyone else might be looking into doing what I'm trying to do for my site, but I figure I still share my findings on the plugins I tested so far. Thank you all for your help .