I have made (tabs) with wordpress plugins but i need to give it a style what is the best way to do it ?css or jquery?if it jquery can u tell me how?

you can write your own css and overright the old one 

note: not file just overright classes using important 

As a web designer or developer, you can create custom styles for various elements in the content of a WordPress website. These styles can be easily added by editing the HTML. What if the end-user or author of the website is not familiar with HTML? What if the author forgot which element was required for the desired style?

Adding custom styles to the WYSIWYG editor (TinyMCE) interface will allow the user to style an element with appropriate custom CSS without having to remember any code. Simply select the element or text and apply the relevant format using the style dropdown menu available in the visual editor. It is fairly easy to add a ‘Styles’ dropdown to the ‘Kitchen Sink’ in WordPress. Adding custom styles to the visual editor in WordPress is perfect for adding elements such as warning messages, buttons and testimonials.

you can make style using css, its sylesheet language

CSS will help you 

You can give style to elements by tagname , class name or by ID

suppose the your id is "tabs" 

just follow the simple steps

Add the following code into the style.css file. 

#tabs{

 background-color:black;

color:white;

border:ipx solid blue;

}

Explore css more here 

http://www.w3schools.com/css/

If you have added tabs using your / some other plugin then it is really very easy to style them. You can style it by either of following way:

1. By making changes in Plugin CSS files. Better to include your own CSS file in that plugin to avoid any other issue.
2. By making changes in Theme's CSS files. You can add your CSS file on your theme level.
3. You can write actions / hooks to introduce your style in your theme functions.php

You can write your jQuery functions as well using3rd option. I could help you better if I could see some demo.