Dalekmun,

To find out approx. how long it'll take you to find a block do this. First look at either explorer.gridcoin.us or type getmininginfo in your Debug console to get the total network hashrate. Currently it's 28,000 kh/s (or 28 mh/s). Then, divide your hashrate by the network hashrate and just convert it to a fraction that's 1/x

Let's say your hashrate is 300kh/s. So 300/28,000 = 1/93.3 so you'll find approx 1 block out of ever 94. Each block is 2.5 min so 94 * 2.5 = 235 min = 3 hour 55 min.