Congressional correspondent Ed O'Keefe offers his take on what to watch for on Capitol Hill every Monday that the House and Senate are in session.

Congress returns Monday evening from its two-week Easter recess with plans to plunge into three substantive issues of concern: gun control, an overhaul of the nation's immigration system and further debate on the nation's fiscal policy.

(REUTERS/Joshua Roberts)

With the House deferring action on guns and immigration until the Senate acts, the lower chamber will spend the bulk of its first few days back debating President Obama's budget plans and assorted legislation on job creation. In the Senate, debate turns first to guns, with some eagerly anticipating debate later in the Spring over immigration.

Looming over whatever Capitol Hill decides to do is Obama, who plans to use his bully pulpit this week to pressure the Senate to act on gun legislation, while also keeping close tabs on the fiscal and immigration debates.

As Jackie Calmes of The New York Times writes today, "The president’s three pending priorities are shaping up as test cases for how he and Republicans will work together -- or not -- in his second term. Each measure -- on the budget, guns and immigration -- in its own way illustrates the fine line that Mr. Obama must walk to succeed even with national opinion on his side."

With that in mind, Obama plans to dine Wednesday evening with another group of Republican lawmakers and conversation is sure to be dominated by the big three issues of the week.

So what exactly is Congress planning to do this week? Here's your trusty road map:

1.) Will there be a new bipartisan gun deal?: Prospects for a deal look better with word that Sen. Joe Manchin III (D-W.Va.), a key moderate eager to broker a deal, has spent the past few days crafting the framework with Sen. Patrick J. Toomey (R-Pa.). Manchin and Toomey are developing a measure to require background checks for all gun purchases except sales between close family members and some hunters, which addresses concerns of some conservatives, according to senior Senate aides familiar with the talks.

If he sticks with the talks, Toomey's inclusion should provide Democrats with the other GOP co-sponsor they've been seeking for weeks. The Pennsylvania senator is usually a reliable conservative, but he faces reelection in a Democratic-leaning state in 2016. He's also one of several GOP senators who have said that they would be receptive to supporting an expanded background-check program if a bipartisan deal were to emerge.

Potentially complicating any movement on the gun bill are at least 13 Senate Republicans, who vow to block the legislation once it comes to the Senate floor. The group is led by Sens. Rand Paul (R-Ky.), Ted Cruz (R-Texas), Mike Lee (R-Utah) and Marco Rubio (R-Fla.), who all participated in Paul's nearly 13-hour filibuster last month.

2.) Will an immigration bill be unveiled this week in the Senate?: Maybe. According to The Post's David Nakamura, the bipartisan "Gang of Eight" senators working on the issue is attempting to craft an agreement so secure that they'll oppose amendments to its core provisions. That's a plan that could further delay the introduction of an actual bill.

The group is still working on issues related to new visa programs for agricultural and high-tech workers and hasn't reached accord on a guest-worker program for low-skilled foreign laborers, aides familiar with the talks told Nakamura.

Another potential reason for delay? Writing the actual bill, which is expected to be up to 1,500 pages, according to some aides. And we all know how much lawmakers love reading and debating thousand-page bills...

3.) President Obama's budget plan set for release: The White House got ahead of itself by announcing details last week (in part to distract from the weaker-than-expected jobs numbers), so we know the basic tenets of the plan: It would cut Medicare and Social Security and ask for less tax revenue than sought in previous years. The plan also revives the offer Obama made to House Speaker John A. Boehner (R-Ohio) during the “fiscal cliff” talks -- which included $1.8 trillion in deficit reduction through spending cuts and tax increases.

Republicans seemed nonplussed by the plans -- saying they've seen this all before. But the budget plan is sure to upset liberals even more, who are concerned he's ceding too much ground after winning such a resounding victory last November.

The budget will be formally unveiled Wednesday and House Republicans plan to hold a vote on the proposals as early as later this week, according to some GOP aides. As usual, the vote is expected to fail in the Republican-controlled House.

(Looking for a reminder of how the "normal" budget process works? Then make sure to read this explainer written by Josh Hicks, a.k.a., The Federal Eye.)

Frank Lautenberg, pictured here in 2006, will not run for another term. (AP Photo/Charles Dharapak)

4.) Where is Frank Lautenberg? (And other comings and goings): The New Jersey senator announced late Friday that he won't be in Washington again this week as he continues seeking treatment for and recovery from "muscle weakness and fatigue," according to a statement.

"My physician continues to advise me to work from home and not travel at this time," Lautenberg said in the statement. He said he'll be disappointed to miss a scheduled Senate confirmation vote of Patty Shwartz to serve on the U.S. Court of Appeals for the Third Circuit and for the opening of debate on the gun bill.

He's already announced he won't seek reelection, and contrary to some reports, Lautenberg aides over the weekend strongly insisted that he has no plans to retire before his current term expires in January 2015. An early departure would be a big blow for Democrats, as popular New Jersey Republican Gov. Chris Christie would get to name a successor, who would enjoy the trappings of incumbency if they chose to seek a full Senate term next year.

In other comings and goings, the political world will keep tabs this week on the movements of former Sen. Scott Brown (R-Mass.), who is publicly toying with the idea of running for the Senate from neighboring New Hampshire against Sen. Jeanne Shaheen (D-N.H.).

And a few members of the House used the two-week recess to announce new political plans: Rep. Bill Cassidy (R-La.) plans to run against Sen. Mary Landrieu (D-La.), while Rep. John Fleming (R-La.) took a pass on the race. In Georgia, Republican Reps. Phil Gingrey and Paul Broun announced plans to run for the seat being vacated by Sen. Saxby Chambliss (R). Peach State political observers are waiting to see whether Rep. Tom Price (R-Ga.) also jumps into the Senate primary.

Follow Ed O'Keefe on Twitter: @edatpost