if i have an album that is a little too quiet and need to raise the overall volume, will this affect/change the sound quality?

I assume you're refering to the soundcheck feature - it's doesn't alter the encoded audio, it simply writes a value to the file's tag and adjusts the volume on playback.

There's no general answer to this question. It depends on the dynamics of the album whether a volume adjustment will introduce clipping and therefore sound quality degradation. I commonly do not recommend to raise the loudness of an album that was released in the late 90s and later, since these ones are notorious for being victims of the infamous Loudness War.

To verify whether increasing the volume level is possible without introducing clipping check a few of an album's songs in a wave editor. If the results look similar to this one...



... then don't even try adding to the volume. If they look like this...



... then some addition to the album's volume is possible.

im not sure, but i think its something different than "sound check".

i mean when you select a song (or songs), right click to get the info, and go to options.

AFAIK the iTunes "Volume Adjustment" is just a playback instruction and won't change the data of the original audio file.
Your screenshot shows info about a Bach Cello suite. It's unlikely that you'll ever be able to make that sound as loud as modern pop music without introducing severe clipping/distortion. Just try with the iTunes Volume how much you can increase the "Volume".
IMHO the best solution to match loudness of various audio files is to play back the loud ones softer. Apparently there is some psychological barrier to do so.