go with C# and ASP.NET. you can use C# in ASP.NET and continue to use what you learned in C#. object oriented programming is pretty important in software development and it makes ASP.NET pleasantly modular. it's also used to make things modular (among other things) in game development and other programs.
you don't need to learn C before C++. you automatically learn the C you need in C++ by learning C++ (don't waste your time)
===Databases!===
but more importantly, ASP.NET, PHP, Ruby-On-Rails etc... all create "dynamic" pages and are nothing without a database. i don't understand how all the other answers left this out. this is generally where all data is stored like the answers on this page. dynamic pages display based on what data is stored. since this data can change, they are dynamic. databases are used everywhere where massive amounts of data has to be stored like banks, government, online games, company data... etc not just for web sites.
databases are generally accessed through queries/commands in the language SQL.
===JavaScript===
you could learn JavaScript (completely different from Java) to make the pages more interactive for the user (think of what pops up here when you hold your mouse over a user-name here). basically it's everything that looks special and can change without reloading the page, but you could also use AJAX in a lot of cases, which contains some ready to use JavaScript components. AJAX can be imported into Visual Studio. an ASP.NET version is documented and available here:
http://www.asp.net/ajaxlibrary/AjaxControlToolkitSampleSite/
JavaScript it's not essential but it can complete things.
(JavaScript is built into most browsers but Java needs to installed by the user to name one superficial difference)
but JavaScript/AJAX is really something you want to do when you are comfortable with ASP.NET or whatever web language you choose, and HTML (it's a luxury).
===my advice: learn C#, ASP.NET and Databases===
- learn to write and design object oriented programs
- use ASP.NET:
Beginning ASP.NET 2.0 with C#
is a tutorial style book with lots of coverage and even some HTML in the beginning (there are probably newer editions). Visual Studio is the best for developing in ASP.NET, you probably won't see a nicer interface than it in other web languages (comes with a database server too).
- learn about database design through ER diagrams (tools like "Dezign for Databases" can generate databases from these kinds of diagrams) (and SQL queries: insert,select,update,delete. to access databases)
http://www.w3schools.com/
w3schools shows you how to make queries.
==other things===
you can pickup up most languages easily after learning C# because most are C like. but C/C++ tend to have more details. that's a reason not to go for Visual Basic (it's not C like and it's ugly).
batch files/scripts are not that important when you can already write your own programs to do the same, especially in C# (another luxury).
unfortunately i don't know any suitable guides for database design and object oriented design, as i mostly learned this in school and haven't seen guides i like.