Dantodd's advise about carbonation is true.
But from my experience you'll need to condition you beer for a month at fermentation temp. to get the best tasting beer you can have. I think cold conditioning of ale just slows or stops the process.
It makes absolutely no sense to me to carbonate your beer before it's properly conditioned (but I don't think it would make all that much difference but don't know as I haven't done that or a side by side comparison). After you transfer to the keg a little squirt of CO2 then popping the pressure relief valve to purge any oxygen wouldn't hurt. Some people do that a couple of times, and some others claim it helps seal the keg.
No matter what you decide to do consider trying this:
Try not to aerate your beer as you transfer it to the keg.
Test your keg for leaks. You can do that by brushing a Star-San solution or a mild solution of soapy water on the keg lid, pressure relief valve and posts after you have pressurized it. If you use the soapy water be sure to thoughly rinse it off. If you have a leak you would see bubbles expanding and bursting as you brush the solution on.
Another way to test for leaks is if you purge the oxygen by pressurizing the keg then releasing all the pressure the keg should repressurize and a day later it should have pressure on it again from the fermentation process. I don't bother with any of that I just check to see it the keg has pressure a day or so after I transfer.
Again some people claim the you need to pressurize the keg to get a seal. I haven't found that to be the case but that doesn't mean it's not true for the keg they have on hand.
After about a week of conditioning, drink a glass, then after the 2nd week try another glass, and another glass on the 3rd week. by the end of the 4th week you should notice the beer is much better than all you previous tastings and that it got better with each passing week.
I've had beer I considered throwing away when it was 2 or 3 weeks old but let it continue to age and by the 6th week there was a vast improvement in the taste.
I guess some of the confusion came because you only asked how to carbonate your beer and so that's the advice you got. Also since most beginners bottle their beer the natural carbonation process and the conditioning process occur at about the same time frame and temp. so there is usually no need to mention it.
But when I read your thread it seemed to me that you intended to drink it as soon as it carbonated and nobody had mentioned condtioning your beer. So I wanted to make sure you were aware of the need for conditioning. And wanted to make sure you were aware that the beer would get better with a little bit of age. So that you would enjoy the fruits of your labor to the highest degree possible. Sorry if I contributed to your confusion. Hope some of this helped and did not further add to the confusion. Best wishes