Chilies need an early start to get the best harvest you can from them. The chili plant is one which thrives in a hot climate and if, like me, you live in a temperate zone then the longer you can give then to develop the better. I have to grow mine in a greenhouse to get the best from the type I grow but I still start them off early.
I am planning on starting some chili seeds this morning and there is 6 inches of snow on the ground outside. I start the chilies in little plug trays which have individual cells and will sow a single seed in each cell. Sieve some compost over the top of this and then you need to put the seeds somewhere warm. The seeds will need at least 15C to germinate but higher is better and 20C to 30C will be better. Some chilies, such as Habanero, can take as long as a month to germinate so be prepared for a wait but most chili seeds tend to germinate a lot quicker than this. I tend to germinate most of my seeds on a kitchen windowsill in my house but with chilies I use a heating pad to provide extra warmth.
Once the seeds have grown you can reduce the heat and I tend to move them on to the windowsill rather than heating pad. When the seedling starts to develop, and you can judge this as the roots start to grow through the bottom of the cell it is time to plant the seeds into pots. As I grow my chilies in a greenhouse I always use new pots so as not to introduce any disease from old pots. I do reuse the pots but not for greenhouse plants. Pot your chilies in to compost suitable for seeds and remember to handle the chilies by their seed leaves only. This is to avoid crushing the stem of the developing plant which will cause it to die. As I grow mine in small individual cells, it is easy to push the complete root ball out of the cell and plant this in the compost in a new pot. This avoids a check to the growth of the plant as you are not disturbing the root.
Continue to grow the plants on a windowsill inside your house when it is cold outside and do not plant them out into your greenhouse or the ground too early as you need to avoid frosts and cold spells.