best way to build mass, lose a little fat

[Azygous]

so i've been a pretty skinny kid most of my life (currently 160lbs and 6'2"), i was on swim team for a few years but i've never had much tone. however, in the last year i've started running at least once a week or more. in the past few weeks i've tried to run 3 times a week (3-6 miles) and i'm trying to go to the gym 3 times a week.

my primary goal is to be able to eventually run a marathon and finish a triathlon. i'm planning on taking up swimming again once i start my job in november as a lifeguard.

my other goal is to see exactly how much out of my body i can get, in terms of muscle:fat ratio and in terms of strength, endurance, and agility.

i think i've finally overcome the motivation hurdle, (and i'm planning on buying a new mp3 player to help things along) but i want to make sure i'm making the most efficient use of my time.

does anyone have any advice on how many times i should run, swim, bike, weight-train a week? what kind of weight-training? should i try to increase proteins and decrease fats in my diet? what kind of helpful bedroom exercises can i do without weights?

[zoebird]

most triathletes train twice a day--check out Trinewbies.com for good information about training.

when i was doing the training, i did functional weight training twice a week for thirty minutes. that was it. i gained muscle and strength. I did my other trainings (run/bike/swim) in intervals. i did yoga every day (at least 30 minutes).

functional training was squats, benches, overhead press; deadlifts, rows, and chin ups. that was the two day split. each day i also did weighted crunches and side bends. the workout took about 30 minutes and i would follow with 45 minutes of interval trianing on the bike or running.