Dear BHA,
As u r planning a 10 day trip, i would suggest that the following itinerary-
day 1- Cochin that is if u r landing there,
places to see- Jew street, jewish synangoue, st. francis church, chinese fishing nets, mattanchery palace are some of the prime destinations.
You would need 2 days in cochin. after that
Day 3 n 4- Kumarakom or allepey- Both are backwater destinations, u can relax and enjoy . There are overnight house boat cruises or 8 hr cruiuse to chose from.
Day 5 - You can head to munnar, its paradise, u wont regret goin there. Its a hill station, there is a national park with one of the rarest species of goats found only there in the entire world. There is a beautiful dam called mattupetty dam. One day is enough in munnar.
Day 6- You can head to thekkady. Wild life sactuary, hiking, boating u name it, its der.
Day 7- Head to Trivandrum. Tke rest if possible. You will be really tired with all these travelling

.
Day 8 n 9- Trivandrum- Kovalam Beach, Museum, Temples, u name it , u will get to see it there.
Day 10- Rest n hope that is enough.
Hope the above is clear and incase any doubts, ask me, surely will help u out, to get a good package for u
sheeba