Make sure you align the midi/piano roll in sync with the tapping of the metronome ^v^ Notes in songs usually are either an entire note lenght, 1/2nd, 1/4th, 1/8th, etc. I first usually determine the tempo of the song by using this pretty handy program called MixMeister BPM Analyzer ^^ 9 out of 10 times, it gives you the correct tempo ^^ Here's what I usually do whenever I midi: I've made quite a couple of UST's using midi's I made in FL Studio before ^v^ So.
