Searchable by title, band, quality and instrument, the Ultimate Guitar Tabs Archive boasts more than 300,000 different user-generated tablature. First, search by name or band. When the results appear, you can filter them by type (tablature, chords, power tab, guitar pro, video lesson) or instrument (bass, drums).
Note: "Power Tab" and "Guitar Pro" tabs can only be read with a purchased copy of the respective software. Despite the $20 cost, these tabs are generally the most accurate, and feature multiple instrument parts, including percussion, lead guitar, rhythm guitar, keyboard and more.
Meanwhile, the regular "Tab" and "Chord" tablature formats usually consist of chord names written above lyrics. Depending upon the song, these formats might turn out to be more than adequate - it is your call.
A power chord isn't so much a "chord" as it is an "interval." Composed of three notes strummed at once, a power chord consists of a root note, a perfect 5th (7 notes above the root) and the root note repeated at a higher pitch. These "chords" take a maximum of three fingers to play, the strings are all right next to each other and using them lets you skirt various "formal music theory" issues. If you press a distortion pedal while strumming a power chord, it really helps fill out the overall sound.
A great example of this is the opening riff for "Smells Like Teen Spirit" by Nirvana. The four power chords used can be played on the same three strings (E,A,D) with the same fingering; you just have to slide your hand up and down to different frets.
Italian for "broken chord," an arpeggio consists of plucking the individual notes of a chord over and over again. To sound good, you will probably need to finger a "true" chord (major, minor, augmented, diminished, 6th's, 7th's, 9th's, etc.) as opposed to a power chord. However, with a little practice, arpeggios can make you sound technically proficient without having to switch between a bunch of different chords.
That said, repeating arpeggios usually sound better with slower, ballad-like songs. For example, try "Adam's Song" by Blink-182, "Hotel California" by the Eagles, "Wake Me Up When September Ends" by Green Day, "Boats And Birds" by Gregory & The Hawk, or "Everybody Hurts" by REM.
Ironically, arpeggios are kind of the precursor for a technique called "sweep picking" - a staple of insanely-fast, hardcore metal solos.