Some links:
Bust the Net - Rashiddi's channel - Torino series is highly recommended
Links to Guides on SI's tactical forum
Very Fluid - Ozil to the Arsenal has several threads on the SI forum that are great but this is his most recent. Highly influenced how I go with tactics now
http://www.fm-ManUMad's thread - great stuff, some tactical musings and some links
I can't access it from where I am but the Stikerless blog by Guido is great stuff.
A few other thoughts....
-watching is vital. On full if possible, comprehensive otherwise. The old 2D, while less pretty, is often the easiest for tactical analysis. Don't JUST look for goals conceded - chances created and not taken can tell you just as much or more. And on the attacking side, having a bunch of attacks fizzle out and not even really be a highlight can be the root of a problem.
-again, analyzing and tweaking is much easier with a clear idea of how you want to play. How is your team going to defend? How you are going to attack? Where is the creativity going to come from? How are you going to get movement between lines? Be reasonable and logical in how you expect things to work - don't take over a 12th division amateur side and expect Barcelona like passing.
-again, minimize TIs and avoid PIs at first. PIs can be really valuable in getting a role to perform in a certain why. But you need to find the right role first. Again, I worry more about the role and duty fitting the tactic than being ideal for the player. If you decide you want to try to keep a solid team shape as a form of defending, but you use a BWM because that suits your player, you may find the aggressive ball chasing pulls the BMW out of position all the time. Maybe you are okay with that because your shape covers, or maybe it leaves a gaping hole that opponents exploit. You need to watch to see.
-realize is there are an infinite number of ways to success. There is not only one "right" way. If you have a problem and ask for help, two different people could offer very different advice. Both could work.
-everything connects. Making one change affects other things. That makes tweaking a lot of stuff at once kinda useless. Its why a ton of TIs all at once can be a problem too. If you don't clearly know what adding a TI is gonna do, why add it?
-recognize flexibility. I've seen people say stuff like "I can only play a 4-4-2 because that fits my players". That kind of thinking is really limiting. Players can be moved to other positions, retrained, etc. So you have more flexibility than you might realize in terms of the shape/formation. But what really matters more than the formation is the way its setup, the roles and duties, etc.
Edit....
-view the tactical process as an on-going one, not a singular process that you "finish". Look to continually tweak and improve, even once you have something that is working. Not to say you should seriously mess with a winning formula, but winning formulas rarely stay that way forever.
And please be aware, these are just my thoughts and suggestions (mostly borrowed or outright stolen), not the "right" way or any such thing.