I agree with WePow. Figure out what you want and need or therapy and come up with a list. You defintely want someone that says they work with what ever you want to work on (depression, PTSD...). And one of the first things they will ask you once you are comfortable is what are your goals... so this will give you a jump start on question one .
There are therapists who work from every theoretical framework and will work with what you want to work on. Make sure that their theoretical framework fits with what you need and believe would benefit you. I wasted a lot of time and money going to people who worked in ways that didn't work for me. The therapist should be able to tell you about the theory they work from so listen to see if it makes sense to you. You can also look up any of the theories online and find more information or ask here to see if anyone sees that kind of therapist and what it is like for them. No therapist will give you a hard fast timeline but you can also ask about how long they work with a client on average. A psychoanylist will typically work with a client much longer than a Cognative Behaviorist.

You also want to know if you want a more "warm fuzzy" T which given your post I would assume or a "directive" T. I have found both to be helpful at different times and some T's can do both.

I worked with:
a psychoanylist but their style of work was a lot of me talking and some feedback from them. I found it too slow for me and frustrating.
an Object relations therapist and frankly they just pissed me off and we fought.
a family systems therapist who I found helpful in understanding how relationships work or in my case why they didn't work.
a Cognitive Behavioralist therapist who really helped me build skills to overcome flashbacks and body memories and build a "tool box" of skills to use. This is also called CBT and a lot of people here work with this kind of therapist and it is one of the "in" therapeutic styles right now. Insurance providers work best with this kind of therapist as well.
an eclectic therapist. She knew about a lot of different styles and tried to match what the client needed. It didn't work for me but I may not have really been ready to work yet either.

They all work or there would't be T's using them. It just depends on where you want to go and how you want to get there. And some T's do use more than one style.

There are a bunch of other syles too but those are the most popular. You can also ask a T which major/well known therapist they see themselves the most like in their work and then look up that person and their style.

Or.. I am a little OCD about theories (as if you hadn't figured that out) so you can feel free to ask me. With the exception of Object Relations I can give you a pretty unbiased idea on what to expect if the T is true to the style. I have read the foundational works of most major therapies because I wasn't finding what I was looking for. Come to find out I kept going to T's who used the same kind of therapy that wasn't working. Wasted at least 10 years of weekly appointments and thousands of dollars. I also know where to find accurate web pages (usually their supervising body) for most styles as well.

My guess given what I have read from your post is that you want a warm (but perhaps not warm to the point of fuzzy) therapist who practices CBT.

Trust your gut/heart!