Yes, you should start on them. Titrate according to how your pdoc instructed you, assuming he/she instructed you. If not, the guys over at crazy meds seem to know their stuff.

Lithium is suppose to be real good at getting people out of mania quickly. It's one of the oldest meds used to treat "manic-depression." That, and the valproates. (i.e., Depakote)
My pdoc brought up Lithium as an option to take in conjunction with Lamictal, but decided that Depakote was a better choice because I've been on it before, with no significant side-effects, other than a lot of weight gain, but that was on a really high dose. Also, I'm on Depakote ER, so I'm hoping that really minimizes the chance of weight gain.

Plus, Lithium just sounds cool. It's an element and in the periodic table.
Just watch out for any significant side-effects, but take it as prescribed and give it a chance.