The bill does three basic things:

1. "Bundling" disclosure. It's a common practice in political fundraising these days to seek bundled contributions. Individuals collect large sums of money from friends and then donate all this money to a candidate as a package. (During the last campaign, Abramoff was designated as a "pioneer" for raising over $100,000 in bundled contributions for President Bush). These pioneers were well taken care of. This bill would mandate disclosure for this.
   
2. "Astroturf" disclosure. Big companies have little trouble faking grassroots support. Using vast sums of money, they can pay citizens to contact their legislators in support of the company's favorite legislation. Recent infamous examples of this include an anti-net neutrality group called "Hands off the Internet" that was funded by the telecommunications industry. This bill would require disclosure of any paid campaigns that spend at $100,000.
   
3. Fixing the revolving door. It is common practice for former members of congress to go to work lobbying their former colleagues. About 200 former Congressmen and thousands of former staffers now do just that. Current ethics rules prohibit Congressmen from working as lobbyists for one year. This bill would extend the "cooling off period" after leaving Congress. Former congressman would not be allowed to be employed as lobbyists for two years - one full session.
   

As the  New York Times says:

This bill doesn't solve all ethics woes, but passing it would be a great first step. There is, of course, so much more work to be done, including on clean elections, redistricting reform, voting machine reform, and the creation of an independent ethics commission. As we head into summer, we hope that Congress finally listens to those outside the Beltway and makes ethics reform a real priority.