I plan to offer an electrum bitcoin payment address to an online shopping cart for services rendered. Roughly once a week forward the coin in the wallet to an exchange and cash out.  I am not so much interested in playing the high/low market strategies for bitcoin, mainly collecting payments and cashing out. 

What is the best way to do this?  Should I do it daily, weekly, monthly? is there a preferred exchange for businesses?  Are there any other considerations?