When it comes right down to it, submission is a waiting game. There are several ways to handle it, and you have to choose which one works best for you.
Personally, I prefer to keep busy. I send something off, have a couple of days of nerves, throw myself back into work...and I tend not to dwell on the submission until either close to the time I know I should be seeing an answer OR when I see an answer in the in box or postal box.
But, there are others that don't work that way. Some can't stand the wait for an answer. One friend of mine...who will remain nameless...hates the wait for answers so much that she avoids most major venues entirely. It's a bit extreme, but if she really can't get any work done while she's waiting for an answer, a two year wait would be ridiculous for her. I would suggest meditation exercises to her, but that's just me. Grin...
Like my friend, many authors literally hover over the in box or postal box. Most of them can still produce new work, but it seems that submission that's outstanding is always in the back of the mind, niggling at them.
Some people are completely oblivious to submissions they have outstanding. That one is almost as dangerous as being SO aware that you can't produce new work. Why? If you "forget" that you have it submitted and submit it elsewhere, you aren't going to make friends when both offer you contracts on the same piece, especially if they state no double submitting is allowed. On the other hand, if you don't pay attention to submissions, chances are you'll forget that something was rejected and not send it back out in a timely manner, costing yourself time.
So, what's the best way to go about tracking submissions? It really depends on the type of person you are.
If that submission...ALL of your submissions...are so clear in your head that you can't flush the awareness of them...of precisely how long it's been sitting on someone's desk, you probably don't need to do much more for yourself. You know when it went out. You know how long an answer will PROBABLY take. You know where you are on that timeline. Nothing more needs done, unless you know you're wildly overdue for an answer.
If you're the type that either puts it out of mind for the duration of the expected review period or puts a submission completely out of mind, you may need to do a little more. I have been known to keep a database that lists outstanding submissions. It has the title of the piece submitted, who to, when it was submitted, any indication I have of how long it should take to make it to an answer...and any updates I ask for or get spontaneously along the way. It's saved my bacon before.
Now, e-mail submissions do make life easier. Why? You can search when you sent it...or for everything from the company/editor/agent you submitted it to. If you're submitting paper copy, it's not much help, I know.