is it possible to burn 2 movies onto 1 dvd-r disk?

i'm new to burning dvd's and i was wondering if it is possible to burn 2 movie's onto one dvd. i use convertxtodvd first and then i burn my movies onto disk with imgburn. i have noticed that when i go to burn a movie with imgburn (after it has been converted first, of course) i have to first click on this calculator symbol. this shows me how much room i have left on the disk after i burn the movie i'm working on. sometimes there is quite a bit of room left. i'm told that a normal dvd-r disk holds up to 3 hours. that could easily hold 2 movies, depending on the movies and how long they are. i tried putting 2 movies on one disk once and when i put the disk in my dvd player it said there was a "disk error". (not to mention, i had no idea how it would look on the menu. i'm assuming it would show one movie with allot of chapters.) that whole dvd was ruined and went to waste. i hate to keep wasting dvd's while i'm experimenting. i also have a bunch of half hour disney shows that i want to burn onto one disk for my kids. if each show is only about 25 min long, i should be able to fit close to 6 on one disk. lastly.....if i was to download a half hour disney show off of you tube and it comes in 3 parts, would convertxtodvd put those 3 parts together to combine them into the one episode and if i had a few of these, say 3 episodes broken down into 9 pieces....would i be able to put them onto a disk that would show them as 3 episodes on the menu? i'm not all that good at burning yet. i use imgburn because it was the easiest one i could figure out. does anybody suggest anything different or better?