1. The Raven
Form and Meter

2. Rhyme Scheme A,B,C,B,B,B
Line 1: Once upon a midnight dreary, while I pondered, weak and weary, A Line 2: Over many a quaint and curious volume of forgotten lore – B Line 3: While I nodded, nearly napping, suddenly there came a tapping, C Line 4: As of some one gently rapping, rapping at my chamber door – B Line 5:"'Tis some visitor," I muttered, "tapping at my chamber door – B Line 6: Only this and nothing more." B

3. Meter
As far as the meter goes, we can start by counting out the number of syllables.
The first and third lines have sixteen syllables each. That makes eight pairs of syllables.
The emphasis in these pairs is usually placed on the first syllable: (Once u/pon a /midnight/ dreary).
This kind of syllable pair is called a trochee. Since there are eight syllable pairs in a line, we call it "octameter" (octo- standing for eight, as in octopus). So the meter is called trochaic octameter.