Also, I keep seeing "indices" mentioned. I don't know what these are or how they affect the BS or count... does anyone have a reference I can use?
Say that for the count system you eventually choose, you find that the index for 10-10 vs. 6 is +8. This means that when the count is below +8, you don't split the 10's, but when the count is above +8, you do split the 10's.
Indexes fall into these categories: Hit/Stand, Double, Split, Surrender, and Insurance. Most indexes work as I indicated above: at counts below the index, do the less aggressive move (that is, Hit rather than Stand, Don't Double, Don't Split, Don't Surrender, and Don't Insure), while at counts above the index, take the more aggressive action. Some indexes, though, are reverse indexes: for these, you take the more aggressive play below the index, and the less aggressive above the index. One example of a reverse index is the index for 8-8 vs. 10: split when the count is below the index; don't split when the count is above the index.
You can get the indexes for your particular count system in various ways. For HiLo, as Panama Rick has indicated, the indexes are available online. With a bit of searching, you can also find indexes for other systems online. You can also get indexes from books: for example, in Professional Blackjack, written by our very own moderator, you can get indexes for both HiLo and Halves. The final method to get indexes is to generate them yourself. I have used QFIT's CVIndex to generate them for the games I play.
Finally, with respect to indexes you'll often encounter the phrases "Illustrious 18" and "Fab 4". These are the 18 most-valuable non-surrender indexes, and the 4 most-valuable surrender indexes. The concept was introduced by Don Schlessinger in Blackjack Attack. His point is that, of the total gain a player can obtain by using indexes, these are the most valuable to know.
Hope this helps!