[Newbie] ubuntu's update-manager???

[David Armour]

hello list

ubuntu's update-manager, a feature that locates it midway between XP and 
BSD/other linux OSs in terms of user-friendly convenience, could still 
benefit from a more informative interface. i'm using dapper beta flight 
6 (i think), and have more or less obsessively applied all the 
recommended 'updates' daily in the intervening weeks. some questions remain:

1. from the More Information, Please Dept... "software updates correct 
errors, eliminate security vulnerabilities and provide new features" 
sounds benign. the boilerplate text under "you can install X updates," 
however, leaves unanswered: what's recommended? all of them? if not, 
which ones can i safely / optimally ignore / apply? What contributes to 
the # of updates? Can I do anything to reduce the number?

2. when update manager says it's  ...downloading 43 of 81files? (...  26 
m17s remaining) ??? ...with a 53.1Mb download size.... and it does stuff 
greater or lesser than this EVERY day, what's up with that?

any help filling in these gaps in what i humorously call my knowledge 
base greatly appreciated. i really appreciate ubuntu's user-friendliness 
(a working printer alone puts it in a whole 'nuther category as far as 
i'm concerned) and i'd like to understand the inner workings better, if 
possible.

tia.