There are lots of different compost 'teas' a good one is to steep comfrey in water for about a week.

it's about 4 weeks for comfrey tea and the same for nettle/chickweed tea. the latter is more readily available should you not find comfrey to buy. just make sure you dilute to 10:1

http://www.allotment.org.uk//vegetable/comfrey/index.php

it's absolutely a must-have plant if you're into permaculture/organic growing as it's got such amazing qualities and uses. i have a 8' x 3' bed of Bocking 14 at the lotti and make around 3 cuttings per season which gives me plenty for tea-making, some mulching and compost accelerator material!

Comfrey makes a fantastic tea if, as Irridium says, you ferment it in 10 times the volume of water for 4 to 6 weeks. It stinks to high heaven so make sure your container is well away from the house. You can make a very concentrated version by cutting the base off a large plastic bottle, cutting two small holes to thread string through then packing it with comfrey and hanging it upside down. The screw top should be removed and a receptacle put under it to catch the slush that falls through. As it rots down keep topping up the hanging bottle with more comfrey. After a few weeks you will have a very concentrated comfrey tea which is easier to store than gallons of the usable strength. The concentrate should be diluted at least 1 to 10 for use. I find this most useful when feeding tomatoes on a regular basis.

However there should be no need to feed seedlings as the fertiliser in compost usually lasts for some weeks. (assuming you have pricked them out into ordinary potting compost from the seed sowing one)