I thought this might be something that could help a few of you out. If you have any to add, please do so because I would like to have as big an arsenal as possible. It probably requires a little more work than something you pay for but...you do the best with what is available to you.
https://adwords.google.com/select/KeywordToolExternal :kind of the obvious one here. There are some other pretty good Google Adwords Tools available but this is where you start, imo.
Free keyword suggestion tool for SEO, Adwords & blogging : kind of a basic keyword tool. Just gives you a solid amount of keyword phrases to work with. Wordtracker has a few other free tools that I use that offer a little variety on the research.
Keyword Questions – Keyword Research Tool : One of the WordTracker tools. Phrases your keyword in questions that have been asked. This offers some pretty good choices.
Google Trends & Wordtracker mashup | GTrendsThis is a third WordTracker tool I just recently found that combines their basic keyword tool with Google Trends. Pretty interesting results and stats. It shows you the amount of competition there is for keywords and the amount of times it is searched for and gives you a thumbs up for each. Basically if there is less than 30,000 competitors and more than 100 Google visits daily they recommend it.
Free Search Term Suggestion Tool by KeywordDiscovery.com : Just gives you a pretty good variety of keyword choices.
KwMap.com - A Keyword Map For the Whole Internet : this is an interesting one. It gives you kind of a mind map for the keyword and a list of suggestions. I'm still figuring how to use this more but it looks like it has some possibility.
Hope this helps some of you out there. Like I said, I would love to see what other free tools are out there. if you have had any success or found out any neat things with any of these, please share. I'd love to learn how to take advantage of these more.