at 300 khash you should be doing this if you mining litecoins and selling them @ 0.01658:

Time Frame    LTC Coins    BTC (LTC/BTC at 0.01658000)    USD (BTC at $136.52)    Power Cost (in USD)    Pool Fees (in USD)    Profit (in USD)
Hourly    0.01207888    0.00020027    $0.03    $0.00    $0.00    $0.03
Daily            0.28989309    0.00480643    $0.66    $0.00    $0.00    $0.66
Weekly    2.02925164    0.03364499    $4.59    $0.00    $0.00    $4.59
Monthly    8.69679273    0.14419282    $19.69    $0.00    $0.00    $19.69
Annually    105.81097818    1.75434602    $239.51    $0.00    $0.00    $239.51


from:
http://www.coinwarz.com/calculators/litecoin-mining-calculator/?h=300.00&p=000.00&pc=0.10&pf=0.00&d=1040.89584526&r=50.00000000&er=0.01658000&hc=0.00