Children will usually show signs they are ready to use the toilet some time between 18 and 36 months.
They will start off just by staying dry for longer periods than usual. You might also notice that they are going to the toilet regularly and you'll also begin to see a pattern in regard to the times they are going to the toilet. They will start crying before they need to go, you should always ask them if they need to go to the toilet if they are crying and holding themselves. Toddlers are usually alot smarter than you would think. They will quite often tell you that they have pooped their nappy. Thank them for this and make them feel good about it.
Never push your toddler to speed up the toilet training process. The best way to not get stressed out is to accept that it takes time and it's just part of how things go with kids.
It has been known to help toilet training if you play the toddlers favorite music or even have his or her favorite tv show playing. The more relaxed they are, the easier it will be to push out that poo!
Whatever you do, don't yell at your darling little toddler for not obeying your strict toilet training rules. Be flexible and understanding and everything will work out for the best.