Question: Let's say you have parameters(s) in your LINQ query where clause, how do you handle that?

Here is an example:

```
var peoples= from i in individuals
  where (string.IsNullOrEmpty(lastName) i.LastName.Equals(lastName))
  select i;

```

Answer: 
[101 LinQ Samples](http://msdn.microsoft.com/en-us/vcsharp/aa336746.aspx) you can start with samples from MSDN
The best advice I could offer someone just starting with `LINQ` is get [`LINQPad`](http://www.linqpad.net/). It is an invaluable tool and will speed up your learning process significantly. And it comes with lots and lots of samples that demonstrate, and let you work with, all the `LINQ` operators.