What would be the best way to book my flights?

You can do it easily yourself. Where are you flying from and to where - enter these details into a search engine like travelmarket or momondo. If you are flexible with your dates you can find the cheapest ticket, then book. Easy as that. No need to pay others to do what you can do yourself with few hours in front of your computer.
If you already know where you are flying back from then you can book the return ticket together with your initial ticket as that will often work out cheaper. Just make sure you check multiple destinations in the search engine.
For your flights around asia have a look at air asia, they have a good route network covering lots of ground and if you book well in advance pretty cheap.
Have fun booking and planning/reading about the destinations. That's a big part of the joy of travelling. Just try not to over plan everything and book everything before departure.

Please also consider Laos. A fantastic country full of beautiful people and a stunning countryside. Particular Luang Prabang is lovely.

I will have a look =) I was just wondering if travel gents have access to cheaper flights or something that would make it better to use them. And i might spend a bit of time in Laos but i only have 2 months in SEA =/

No..travel agents are in it to make a profit (obviously..they need to make a living too ;-)

It is practically always cheaper (usually much cheaper) to do it yourself.....

With that itinerary (and that much time) I'd look at an 'open jaw'...booked online.

Say London (are you in England?)-Delhi and then Beijing-London for 8 months later.....

The rest you can go overland or book as you go..more flexibility like that.Stay as long as you want,move on when you want.....

That is a really good idea, i think i will do that. I am going to book London - Delhi, Chennai - Bangkok and Beijing - London. The rest we will plan as we go along!