Q and A section

it depends really, at the end of the day you would would be adding an extra page to your site with useful content so thats always good and it should be pretty keyword rich as you going to be answering quetions on tiopics the site covers.

Without knowing what site its for and just what info will be going on the page it is hard to judge just how effective the Q&A page will be, but dont expect any huge change all it will really be any use for is it should cover questions that people may use as a search term if they are lookinf for the info you put on the page.

Dont think so much as will it benifit you SEO wise but more will it be of use to real people, if it covers the topic your site is about and is usful for people then it will attract more visitors naturally.

As for a forum these can be a great addition for a site as it makes the site much larger as a whole and gets a comunity of people together who are intrested in the tiopic the site covers, the big problem with forums is they take alot of work for them to be sucessful.

Do search engines like Question and Answer sections on a website- is this beneficial for SEO?
And would a Q and A section be good to be a part of a landing page? Or how about a forum?

it'll help the seo if the discussion/topic was related to the site. and best here was yahoo answer.

and forums really helps a lot, if you do it properly. i mean you're always on the topic, and dont be spammy.
forums deliver traffic, backlinks as well as ranking..

I think they will love them, Fresh original content, based on exactly what you want to rank for. So far the advice is true and from experts you have content gold. You need to set it up in a manner that can be indexed properly by the search engines so you can rank for each question(s).
For Forums, Well that's what they are all about in the first place, Question and answer!