Only go IT/MIS if you are passionate about it.
I switched from Production Management to IT/MIS two years ago. Just when the field started flooding from all the dot.com crap.
Through hard work and a few fortunate circumstances, I'm now the System's Administrator of a Medical Device company where I started as a pc build technician.
I say be passionate about it, because that's the only way you have a chance. IT Techs, Network Admins, they're a dime a dozen right now. I get 5-10 calls a week from headhunters & temp houses trying to find work for their clients. I interview temps and potential employees on a semi-annual basis just to keep a resume file current. I say be passionate about your work because nearly every one of the applicants I interview are qualified or over-qualified for the work I'm hiring for. I notice the potential employee who is passionate, aggressive, pro-active about their career field. Even if promising, I tend not to pay attention to the applicants that just seem to be looking for a paycheck or a place to surf.
1. A+ isn't a big deal as far as skill goes, but I won't hire someone who doesn't have it. It just shows your responsible and have applied yourself in a critical area. 7 out of 10 resume's I read have A+ and some form of further IT education - so whether or not A+ is truly critical doesn't matter - it sort of becomes a standard criteria.
2. As far as other cert/training to pursue, you have to figure out which area of IT you'd like to specialize in. You won't have time to be good at it all.
If you're serious about IT, visit local businesses and ask for a tour of the IT Dept. Most Admins and Managers that I know would be more than happy to show you around their digs. That will give you a better idea of an IT work environment and the various roles in IT.
I love my work, but a drawback I've found - is that you have to constantly be watching technology, always learning and keeping ahead of the curve. And, realistically - you have to pursue certification, no matter how good you are at what you do. I'm solid in my position here at this company, and I can Admin a network with the best of them... But put me in the employment line with all the other out of work Admins and Techs, and they'll probably be more current in certification than I am.
That's my 2 MB.
-Sketcher