Prof. Jayanth R. Varma's Financial Markets Blog: Prof Jayant Verma is a Professor of Finance (mainly Financial markets) at IIMA. He is one of the most impressive teachers I have ever met. He was one of the first members of SEBI and is on the board of multiple big companies including Infosys and Axis Bank. His blog, which has been up since 2005, is a brilliant resource on understanding the nuances of the financial markets.
Dealbook (NYT): Dealbook is the news aggregator section of NYTimes to keep you updated on the current state of affairs of the Fin industry.
Mergers & Inquisitions: Everything you need to know about every aspect of the Financial world - from big investment banks to boutique firms, from Private Equity to Hedge Funds and AM/WM firms.
Investment Banking Blog: The holy mecca for preparation of i-Banking interviews, the IB Blog offers everything from boot camps and interview prep courses (paid) to free resources like basic interview questions, an overview of the industry, etc.
Wall Street Oasis: Similar to #2 above, but with more functionality to read the best articles of the month/week/day, etc.
FT Alphaville: Another news aggregator that will make sure you do not have any time left in your day (courtesy its exhaustive coverage of current affairs)
Entrepreneur: Your companion on the entrepreneurial journey. The site will keep you updated with the start-up world, help you work on various aspects of your professional self, and also provide the much-needed pep-talk when you are feeling down/exhausted/defeated.
AVC: The Chronicles of Fred Wilson ( a Venture Capitalist for the past 30 years) with some incredible credentials to his name (including investments in Twitter, Tumble, Zynga, Foursquare, etc). AVC is probably the most widely-read VC blog in the world.
Mad Over Marketing: MoM is a fun blog. They capture everything from brand wars on Twitter, to a collection of some of the best and most important marketing campaigns. The blog is a very easy read and will help you broaden your horizon when it comes to thinking of how you can ante up your marketing/advertising game.
Duct Tape Marketing: Duct Tape Marketing focuses on small businesses and startups. They take into account that small businesses do not have the funds that large corporations do. So their marketing tactics need to be tailored to their financial capacity.
aimClear: aimClear wants to be the single resource when it comes to your personal as well as company brand by using every possible tool in the marketer's kitty - from social media to SEO, from conclaves to data management using basic tools like Excel.
Bufferapp social: Bufferapp is an exhaustive resource to help you manage, grow, and track your social media persona.
HubSpot Blog: A collection of 3 secondary blogs - focusing on sales, marketing, and your agency. This trio will help you streamline your sales activity, boost your pre-sales capabilities, help you traverse the maze of sales-killer questions like, "This is too costly", and also help you manage your time and productivity in a better manner.
Marketing Land: The Dealbook of marketing, ML is the one-stop solution for your marketing trends news requirement.
The SumAll Blog: The SumAll blog is like the child of Buzzfeed and Medium (and not in a negative sense). They post content which is useful and is also written in a fun manner. The articles are often crisp and under a 5-min read.
Freakonomics: The authors of the best-selling economics-infused-with-pop-culture book have more to say and share than the 2 books. The blog is usually a collection of podcasts that aim to explore the "hidden side of economics" and highlight outliers, which although rare, are extremely critical.
Why Nations Fail: On the same line as Freakonomics, the blog by Daren Acemoglu is a follow-up on his book of the same name and explores similar obscure events that shaped the rise and fall of nations and civilizations.
Economixcomix: The companion blog for the graphic novel of the same name by Michael Goodwin, Economixcomix explains the basic tenets of Economics in a simple way, along with illustrations to make understanding easier.
The Grumpy Economist: The perennial pessimist, the one who finds faults in everything, the dad who bores his kid during dinner with his constant rants and criticisms, John Cochrane provides an unabashed, and hard-hitting critique that exposes the not-so-sunny side of the world economy.
Investing and Economics Blog: The Curious Cat blog is for us. The laymen. The dabblers. It focuses heaving on personal finance, economics, financial literacy, tax planning, credit management et al; stuff that affects the majority of the populace on a regular basis.
The Upshot: The NYT economics companion to its financial section, Dealbook, The Upshot is all you need to read to be perfectly updated of what is happening, why it is happening, what would be the consequences, and what could have been done better.
Economist's View: A collection of self-posts and the hottest posts from other economics blogs.
The Money Illusion: TMI focuses on the money and capital markets and provides wonderful commentary on financial crises, international economics, foreign reserve dynamics, monetary and fiscal policies, labor markets, etc.
Guy Kawasaki: Guy is one of the most well-known figures in Silicon Valley and among the first "tech evangelist".
All Things Workplace: As the name suggests, this is a blog for managers, bosses, and professionals and aims to cover all aspects of workplace management including effective communication, employee engagement, conflict management, incorporating cultural diversity and differences, various facets of leadership, boosting creativity, and so on.
Seth's Blog: Seth is a funny guy. The funniest of all in this list. Although he calls his blog a marketing blog, it's more generic in nature and oft has funny quips and clever observations interspersed with long-form articles.
Lean In: Everyone knows the book by Sheryl Sandberg, COO of Facebook. The blog aims to continue the story and encourage and empower women to face challenges, voice their opinions, and grow themselves in the workplace.
Switch & ShiftS&S aims at helping business transition from the traditional workplace model to the current, more information-driven, globally-diverse-yet-connected workplace.
Hot Momma's Project: Don't go by the sexist-sounding name, HMP is sort of a companion to LeanIn and strives to help women claim their rightful place in the corporate world.
Culture University: In a globally interconnected world, understanding, accepting, and imbibing cultural diversity is an important trait for organizations to sustain themselves and grow.
Big Think: Having Bill Nye, TheScienceGuy, on board is a big achievement for Big Think which aims to be an idea hub, a "Youtube for ideas" as its founders put it.
Bob Sutton: Bob, a Professor of Management Science at Stanford, writes on everything including, but not limited to, workplace culture, book reviews, team management, employee management, etc.
Harvard Business Review: HBR is the most popular published management magazine that covers almost everything relevant to an MBA degree. If there has to be a starting point for an MBA student/aspirant, this is it.