Moni, the bedtime routine needs to be accompanied by other factors like atmosphere, winding down and associations. Keep the bedtime routine limited to 20-30 mins only. It needs to be any series of actions or events that always lead up to the time to sleep. Your baby may not get into the groove of it immediately but it will happen in time if you are consistent and stick to the routine. Consistency is the key. Also, start winding down the activities half an hour before starting th routine. Allocate one fixed place where your baby will always sleep whether at bedtime or nap time.
Do use white noise like sound of waves, wind, leaves rustling, or any repetitive gentle melody at bedtime and throughout the night. This association with bedtime will be the strongest and most effective. But it cannot be used alone and will not give you a permanent solution. You must do all the above if you really want to succeed in putting your child to sleep easily.
Also, and this is very important, always put your baby to bed awake. I know it sounds weird and will be quite difficult initially, but that is the only way that he/she will learn to sleep and sleep well.
I had asked you for your baby's existing schedule but you have not given it yet. The reason I want it is that the time at which your baby is taking his nap may also be the reason he's not sleeping quickly. There has to be an optimal time span between the morning wake up time and the nap time, and the nap time and bedtime. If this goes wrong, the bedtime goes for a toss.
Teaching your baby to sleep and sleep well can be achieved but I'd be lying if I told you it was an easy task. I have done it successfully for my son but struggled for many months to get all the information I'm trying to convey to you now. I am telling you again, I can help you if you give me the information about your son's schedule that I'm asking for.