Context is very important here. Are the events and times presented in a list or are the times included in a paragraph of text. (Or both depending on the screen?)
If you have a lot of events and all the times are during normal working hours then the AM and PM may not be necessary.
Lecture 1 ---- Location A ----- 10:00 - 11:30
Lecture 2 ---- Location B ----- 10:00 - 1:00
Lecture 3 ---- Location A ----- 12:00 - 2:00
In circumstances such as what was listed above you may safely leave the AM and PM out as the times would be "understood." There are, of course, many scenarios where that would not be the case (hotel or airline reservations).
In any case be consistent and be as clear as possible. (Which to me means to drop the AM and PM if understood but include if not).
Lots of people (myself included) find it visually more appealing if the AM and PM are set in small caps. However most style manuals are in favor of using a lower case am and pm. For instance the Chicago Manual of Style says that:
Instead of AM and PM (in small caps), p.m. and a.m. -- with lowercase and periods -- are the preferred way to indicate time of day. Other abbreviations traditionally set in small caps would now be full caps.
Should zeros be used in time displays?
The answer depends on scanability which can be measured by using the 5 second test. Namely are people able to locate and absorb the time without the use of :00 for minutes.
Test your users. Which is easier to read, easier to scan among a large amount of text: "The meeting is at 10. Or the meeting is at 10:00" ?
On a list view I think it would depend if all the events begin and end on the hour. In that case the ":00" would be superfluous and may very well be an unnecessary detail.
(Although I, as a user myself, gravitate toward the :00 notation.)