You have to start with the basics. Microsoft provides you with most of what you need. SQL Server Management Studio, while clunky & weird in places, is the tool for maintaining your servers and databases. It's also where you're going to run most of your T-SQL queries from. You need to learn SQL Agent, how to create and schedule jobs. Depending your employment siituation you'll need to learn either Integration Services or Reporting Services or both. I'd also recommend taking the time to pick up on Policy Based Management. Microsoft has also provided you with a great "tool" in the PowerShell language. Start working on learning it even though you're just getting started. For monitoring you can't go too far wrong using the Data Collector. These are all fantastic tools that come, free, out of the box. I'd learn them first. But what you're asking for is third party products. One that I would not want to live without is Red-Gate's SQL Prompt. It's a functional intellisense for all versions of SQL Server. Red-Gate also has a fantastic tool for comparing schema's SQL Compare. They just came out with a new tool that I'm still evaluating but I can safely recommend, SQL Source Control. SQL Source Control plugs into TFS or AVS and lets you treat your database like code. It's fantastic. Those are the ones I'd start with. DISCLAIMER: I'm a "Friend of Red Gate" which is a program where I get copies of their software and take part in their beta programs. I got there because I love their products, but I feel I should mention it when I'm singing their praises.
To get a quick search and smooth navigation between objects (tables/stored procedure) - use [**SQL Hunting Dog**] It is a free Addin for SQL Server Management Studio 2008 / 2012. I have built it. :