2005 is so much better than 1.x. There are a myriad of new freatures in 2.0. You can use MasterPages for your website layouts. There are web parts that would enable a web user to customize a webpage by being able to shift elements around on the page. The DataGrid was replaced by GridView, which is easier to work with. You can also use SqlDataSource to populated Data Controls. The SqlDataSource will save you time so you don't have to write connection code.
2.0 now has local database support. You can add a database right to your APP_DATA folder, which you'll be able to build and connect to with ease. You can only access this database from the project you are working in. If you want to make the database live on a webhost, you have to copy the .mdf or generate script to move it.
Classes now have a keyword called "Partial", which would allow you to have the same class name over many areas. This is so, if you are working in a team environment, many co-workers can work on their own version of the same class without writing over each others' code. At compile time, these same files will be compiled together.
There is just too many things to list on here. If I were you, I would go to ASP.NET QuickStarts and go from there. There is a lot of information you can learn from there.
Also, if you haven't already, download the startkits from ASP.NET. The starterkits are useful and powerful, and not just some cheesy website example.