Welcome to the community.

Keep your coins in a private wallet and then when you need to exchange coins send the requisite amount to btc e and make your exchanges.  Secure, quick and easy, etc.

BTC first and then you can use your btc to buy LTC. 

Both will continue to fluctuate a bit, but now is still going to be a good time to get in because you will never be able to predict exactly how low it will go from here, but it certainly will go up in the future.