First off a matter of verbiage needs to be cleared up.
Just like Hoosiers need to be informed about our licenses being "to carry" vs "concealed", this is another matter that verbiage is, in my opinion very important.
In Indiana (and most, if not all states, including PA and FL) every male "of age" (16-55 on average) is a member of their states "Militia".
By simply being a resident of your state (IN for example) you are automatically (by definition of the Indiana state constitution) a militia member. You don't sign up, you don't choose, you simply are.
So you are already a member of the unorganized Indiana militia... whether or not you choose to join (or start) a 'organized group' is completely up you.
I've never joined a group or attended any meetings, so I cannot help you there. I have seen someone (a couple months ago) post on here they were a member, try and search thru some of the posts in this forum.
As to joining being a good or bad idea...
Militias are what protected and continue to protect our freedoms. They are vital. Specific groups, I cannot comment on. The press often gives militias a bad name. We all remember how they said Timothy Mcveigh attended a militia meeting. One guy attended one meeting and all of militias are bad... thats the media for you. Don't let the negative image of one or two isolated incidents dissuade you from learning more information or pursuing it.
I had thought about it myself a couple years ago and we've had two little ones since then and I'm working more so I didn't have the time and it just dropped of my list of things to do.
Good luck in what you decide and please let us know how things go.