I would like to know which can be given as a good source for a beginner to learn Tridion API methods and functions. Is there any such consolidated documentation on the sdltridionworld?
There are a number of APIs available for SDL Tridion. Here's an overview:
TOM.NET - The CMS templating API, written in .NET, runs on the CM machine
Core Service - A .Net web service API, allows you to interact with items in the CMS from another machine than the CMS server itself.
Content Delivery - This is a front end API allowing you to work with published CMS content, for example in a news page, get all 'published news' - this is .NET and Java
There are a number of other items too such as CMS Event System, Custom Resolvers, Custom Deployers, but the above I consider to be the main APIs.
So if you know for example, 'I'd like to build some website templates' your best place to start would be the TOM.NET API.
SDL does run developer training courses. I'd recommend you sign yourself up to one of these, as there's certainly a lot to get through and the introduction and developer courses cover them very well.
If you have valid sdl tridion world user id, you can download various resources including CHM files, manuals and whitepapers for various APIs.
Below picture shows the link from where you can download the API documentations once you are logged into the SDL Tridion World
I always suggest for new Tridion developers to choose a site (news sites work well) and try to build this in Tridion, from the beginning. This means you will:
Then, you can choose to dig more into the other APIs, such as the Core Service.
I normally plan about 1 week, full time, for the above.
See the link in John's post about the excellent SDL Tridion training courses. If you're not lucky enough to attend those, then I would find a local Tridion expert on your team and try to create your own site from nothing with their support, help, and code samples.