Q: so for instance if i can make 1 ETH a month from one computer if i hook up 7 can i make the 7 ETH a month and could they go to one wallet or do i have to make 7 accounts?
A: Yes, and you will only need one account (or address, or wallet). When any of your computers finds a block, the block rewards will be added to your specified account.
Q: and another thing is can it run while people are doing simple tasks (ex. ms word, youtube, facebook,) or will it lag the computer to the point it only has to stay mining where as i can turn it on at night only when i close up.
A: You computer will lag when you first start up the miner. After starting the miner, your miner will receive new blocks from other nodes on the Ethereum network, averaging 15 seconds between new block on the blockchain. On receipt of the new block, your mining software will reload it's computing problem from your main computer memory to your GPU. You will get a smaller lag when this occurs. My GPU fans normally slow down, then start up again when this occurs. The effects of the lag on other running software on your computer will depend on the speed of your CPU, memory and motherboard. On low-end hardware, the lag is irritating, so best to mine at night for low-end hardware. For higher performance hardware, the lag should not be too bad.
Other Information
The 2GB memory size of your GPU card may cause some hassles. The Ethereum mining algorithm is memory intensive - this is to stop dedicated computer chips being built to mine the Ethereum blockchain. You may have to twiddle with some configuration parameters to get your graphics card mining. See A bunch of 2GB cards stopped working tonight because of DAG file size... - this is for the AMD series of GPUs, but may apply to NVidia GPUs as well.
Based on your additional information:
yea ive seen these articles about the best graphic cards to mine with but my graphics cards are Nvidia gt 610 2gb and have roughly 10 Mh/s and so Calculated Mining Earnings : Duration Ether Earned USD Value Per Hour 0.0056284351922976 $0.04 Per Day 0.135082444615142 $1.05 Per Week 0.945577112305996 $7.34 Per Month 4.05247333845427 $31.45 so im guessing this i would make having my computers turned on 24 hours of everyday?? – park93 7 mins ago
CPU Mining
Not worth the electricity to mine
If your cyber cafe computers do not have graphics processing units (GPUs), you will find some calculations on the profitability of mining ethers on Is CPU mining even worth the Ether? .
GPU Mining
If your cyber cafe computers do have GPUs, you will find some of the expected hashrates (the rate of calculations relevant to mining the Ethereum blockchain) in the following references:
Plug in the hashrates that can be produced by your GPUs into one of the Ethereum mining profitability calculators to work out your expected $$$:
It would be useful if you added to your question the sort of hardware your cyber cafe computers run on. In particular, do they have GPUs? And if so, what models?