'Tis hard to say, if greater want of skill rhyme aa bb, and so on -- a represents the ill sound, b represents the ence sound. A quatrain such as
Appear in writing, or in judging ill;
But of the two, much greater is th' offence
To tire the patience, than mislead the sense
Far from the madding crowd's ignoble strife,is said to rhyme abab, where a represents ife, and b represents ay. More complicated patterns can be described the same way: the sonnet, for instance, can be abab cdcd efef gg or abba abba cdecde; the Spenserian stanza rhymes ababbcbcc.
Their sober wishes never learned to stray;
Along the cool sequestered vale of life
They kept the noiseless tenor of their way
Most rhymes appear at the end of lines, but internal rhyme is the appearance of similar sounds somewhere in the middle of a verse. Words in the middle can rhyme with other words in the middle or words at the end of lines.
Note: This guide is still in the early stages of development.
Three question marks mean I have to write more on the subject. Bear with me.