There's a lot of good advice in here, but may I add my two cents worth since I used to be a beatician and also have very long, straight hair...

I used to use Tresseme products. They're good. Now I use Pantene. Can't imagine what it was like before "creme rinses" and conditioners. I ALWAYS finish up with Pantene conditioner.

For an excellent, inexpensive once-a-month conditioner I use the left over mayonnaise in the bottom of the jar. I learned this in beauty school... not that we used it on the patrons. LOL If you do this, do it before you wash your hair. Wrap it in Saran wrap or a clear plastic bag and either sit in the sun, if you have time, or use the blow dryer on a warm setting just to keep it warm. The warmth opens up "the pores" of the hair and it absorbs better. Why mayo? It has eggs as protein source and certainly has "oil".

Definitely use a wide tooth comb either in the shower with conditioner still on the hair or after the shower to detangle the hair. Start from the ENDS of your hair and work your way up. DON'T rip the tangles out, work them out with the comb. DO NOT BRUSH wet hair! It stretches the hair and it will break much easier even after it's dry. That will cause more tangling.

The reason women used to brush their hair 200 strokes before they went to bed was to get the oil glands going, get that oil as close to the ends as possible simply to make the hair shine. If you have normal to dry hair, go for it but be very careful with the ends. Use a natural bristle brush.

When you start seeing split ends, get a trim. The trim will promote some hair growth... just like "pinching back a plant." Split ends do not stop your hair from growing. What it really is, is hair breakage. UGH!

Flat (to get rid of the bubbles and the drying alcohol) beer is also a good conditioner and it's a "leave-in."