can some one tell me about it ?

What do you want to know? Everything you need to know can be found at www.swtor.com

I'll give you a few little tips.
If the quest has a number by it, thats how many people are recommended to do the quest, I wouldn't recommend attempting to solo a quest marked for 2 people or more unless you're way overgeared, know the quest well, or are above its level.
Be sure when you get a companion and are level 10+ (once you arrive at the fleet) be sure to grab some crew skills. A handy one for your first character would be slicing (one of the 2 gathering you'll need 2 gathering and 1 crafting). Slicing is great because while doing your quests and fighting monsters you'll find lockboxes which have credits inside. You will need all the credits you can get starting up. By pressing N(default) you can view your companions and your crew skills and send your companions on missions for you, this can help a lot in making money and some beginner gear based on the crew skills you choose. Also at level 10 (if you haven't already done this you should do it as soon as possible) pick up your primary class. For example if you chose smuggler, go to your class trainer and decide whether you would like to be a gunslinger (ranged dps without healing capabilities) or scoundrel (healing capabilities and ranged/melee dps (mainly ranged)). This is a pretty important decision because it pretty much decides the path your character takes for the rest of the game.
It may feel like while completeing quests and doing your story line quests you overlevel the storyline quest. I would recommend focusing on the storymode quest until its too hard to complete alone, then work on some quests on the planet that your current story mode quest is on until you have leveled enough to complete your class quest and continue on with the story.
Some things to help keep leveling from getting stale: once you have your ship you can do space missions which are pretty easy (assuming your ship has the necessary upgrades) there are daily quests for these as well located right next to the pilot seat of your ship. Also pvp (you may queue for this once you hit level 10 by clicking your faction's symbol located at the bottom right of your minimap.) You will notice in these pvp matches you will be up against level 10-49's the game automatically raises your stats to match a level 49 character so that you have the fairest fight possible. Of course the higher levels have more skills at their disposal which normally leads to them being harder opponents in pvp so watch yourself when you're fighting a 49.
Hopefully this long post will be of some use to you, you can message me if you have any questions and I'll do my best to answer them. If you're on the harbinger server, you can message my character directly and I can give you a hand in game if necessary. (message me if you want my character name because I'd rather not shout it off the rooftops ) good luck hope you like the game.

This post was edited by Mcgrym on Oct 14 2012 12:22am

This is good game, but i like singleplayer too.

pvp is great. leveling is grindy. pve blows when you have no combat log(people doing garbage jobs of their roles in the game and or dying to stupid things. and you dont know. its chaos. pve is really lame). Lack of players. Bioware didnt do a very good job with the game and overfunded voice acting as oppose to the real game. So pick ur server wisely if you plan to pick this game up. You should have fun though, atleast until you come into full understanding of the games shortcomings.

For those that dont like an honest reply, for example mcgrym and his hype about the game, I'll point out an example. Ilum. If you were playing when this crap got released it shows just how much Bioware failed. and the reworkings of this world pvp zone were not any better. Now if you were on a BALANCED(sith /repulic ratio) server that was populated before the reworking and after was still ok but for everyone else that place was a nightmare and a huge waste of time.

This post was edited by Farmer_W_John on Oct 16 2012 03:06am

Just roll Pyrotech and run around spamming 1 button.