This psalm is one of several in the psalter which are structured around an alphabetical scheme, like an old fashioned embroidery sampler.  Each line of the psalm begins with a succeding letter of the Hebrew alphabet (except for the very lasy verse, apparently an enthusiastic addition to the psalm by a later scribe.)

Though this is a simple technique of the sort elementary school teachers often use with their students, in Psalm 25 it is used with great subtlety and power.  In addition to the alphabetical scheme, the author uses a device called chiasm, a sort of nesting box structure which uses repetition to draw the reader's attention to the central, pivotal verse of the psalm.

All of this careful poetic manipulation goes to waste in the liturgical version of the psalm, however.  Sinced only the first 10 verses are commonly used in worship, the alphabetical scheme is jilted, and the chiasm is cut in half.  To make matters worse, the editors of the liturgy have dissected the psalm exactly one verse before the poet reaches the climactic center of the poem:

"For the sake of your name, O Lord, forgive my iniquities, though they are great."                      Psalm 25:11

Everything else in the psalm... from its simple yet profound statements of reliance upon God to its towering statements about God's faithfulness and mercy... revolves around this single cry of confession and need.