How quick to start weight training?

I'm a 27yr old male, 6'7, and 143lbs. I started a weight gain diet about 2 weeks ago. I've tried off and on for awhile now, but I'm hoping that counting my calories and CC resources should keep me in check. I was just wondering when the best time to start training for increased muscle mass is? Is it something I should start right away or is better if I wait till I gain a few pounds to spare?

Any help/suggestions would be greatly appreciated. Thanks.

exercise is a wonderful thing, bec it's a stress on the body that makes it stronger, whether that be stronger in a cardiovascular way, flexibility way or muscle way.  however, you're exactly a foot taller than me and weigh exactly what i weigh.  i highly discourage any stress at all on your physical self.  i would, however, advise meditation and any form of mind-body connection exercise that you can find time for.

when i was underweight and seeing the effects in bone loss, i received some unbelievably astute medical advice:  "the best weight bearing exercise is to bear weight."  and that's absolutely positively true.