proper shifting

Hi guys, I recently bought a used 1991 trx 350 ( same as '89 foreman)What is the proper way to shift ? let of throttle and then shift ,or just shift ,also I read on forums lots of people start in second ? any problems. can you damage anything if trying to go in too high a gear? also read about not taking hubs apart? hub on axle, can you take the brake drum of without doing this? also welded hub? Thanks Eric