My credit is very low .. how do improve it beside ...

You shouldn't "pay everything off", all you have to do is to minimize your debt, as much as possible. Don't open new bank accounts, but sometimes getting one or more credit cards might help you with a proper loan in each one. On the other hand try to minimize your credit card activity.

 There are no magic tricks- the most influencing factor on your credit score are still debts. 

One thing you must do is to make every payment ON TIME.  The rating will go up after 6 months or so if you have no late payments.

The misconception is that in order to lower your credit scores that you have to pay things off. This is a huge misconception.

What I’m about to tell you is something I have learned through my own experiences, I guarantee if you do these simple things it WILL raise your scores. A friend of mine did what I’m about to tell you an his middle score went from a 640 to a 701 in 30 days, he did not pay off anything he just did what I told him to do.

The way thing used to be: about seven years ago credit worked different than now, it used to be that if you had allot of credit lines your score would drop.

The way things are now: Here it is this is what you have been waiting for. How it works is like this. I have seen credit reports with people having 40 lines of credit open. YES that’s 40 lines of credit open with 800 scores, these people were not rich they were very average. In order to raise your scores you need to look at your debt. if you have three credit cards that are close to the max even if you pay these on time this will be a negative, this is because its showing your near your max of your credit limit. what you want to do is spread these debts out, say you have three credit cards each with a 5K limit and you owe 3,500 to 4,000 on each one, all you have to do is transfer some of your debt to another credit card, you want to lower your balances to 50% or below the limits, also while doing this you will most likely get a better rate with the transfer credit card while lowering your balances on your other cards. This will show that instead of being close to your max, you now have a buffer or more credit that you are not using showing the credit repositories that even though you have all this credit you are not running out and charging everything under the sun and maxing your credit out. This is how my friend raised his score 61 points in 30 days; this is how my wife has raised her scores as well. Try it, it works.
Fico Scores/Reports

http://credit-score-fico-score.blogspot.com/2007/09/credit-scores-and-fico-scores.html

You won't improve it much by paying everything off you will improve it by having all of your

There are several organizations that can help you improve you credit score.  I know of a site at:

Here's a quick steps on how to improve your credit score  Hope this will be helpful to you.

If you are maxed out and delinquent you might want to consider a Debt Reduction program to negotiate these debts down so you can rebuild your credit.  If you need more info try going to this Debt Help site, Select Debt Relief . You really need to get some of the outstanding debt taken care of before you can focus on repairing your credit.   

Have you tried a credit counseling service to help you raise your credit score, and also to help you with credit card payments?