<p>Can somebody please provide me some important aspects I should be aware of while handling Unicode strings in C#?</p>

C# (and .Net in general) handle unicode strings transparently, and you won't have to do anything special unless your application needs to read/write files with specific encodings. In those cases, you can convert managed strings to byte arrays of the encoding of your choice by using the classes in the System.Text.Encodings namespace.