I encourage beekeepers to observe their hives from the outside on a weekly or even daily basis. There is useful information to gain by doing this. You may observe if your bees are bringing pollen or even catch a pesky ant invasion. It’s also a good idea to make yourself familiar with what is ‘normal’ for your bees in terms of traffic (the number of bees flying in and out of the hive), also in regards to the number of dead bees near your hive.
That way you can recognize any changes if and when they happen. Despite these merits, observation from the outside is no substitute for hive inspections. Often if a problem is noticeable from the outside of the hive, it has progressed too far to be remedied. Inspections, when done properly, will catch problems early and give the beekeeper a chance to fix them before too much damage is done.
Inspections also provide new beekeepers with the opportunity to learn. For that reason, I recommend that new beekeepers inspect their hives once every 2-4 weeks, but no more often than that. Inspections are stressful for bees and they disturb the carefully controlled atmospheric conditions within the hive.
Many experienced beekeepers perform less frequent inspections on their older, more established colonies because of this. To a new newbee, this can sound like a catch-22, but I firmly believe new beekeepers should inspect their hives regularly for learning purposes and because it is likely that their colonies are also new and therefore less stable.