Since free agency occurs before the draft, first take a look at positional needs.
 2010 Positional needs (This is a matter of opinion.)
http://www.drafttek.com/teamneeds2010.asp
Washington  (These ranking were set before the ¾ defense looked likely for the Redskins.)    
Offense
QB, RBF, RBC, WRF, WRP, WRS, OT, OG, TE, OC, FB
   1,      5,        5 ,     6,         9,       9,    2 ,    2,    9,     9,   9
Defense
DT43, DT34, DE43, DE34, OLB43, OLB34, ILB, SS, FS, CB, PK
      4,          9,        9,        9,          4,            9,     9,    6,    6,   6,    9
Team Needs Code Descriptions (abbreviated)
1 - This is the absolutely highest priority team positional need.
2 - indicate that the that the team is in great need of starting caliber talent and will reach to fill the need.
If you don’t like the above priorities, select your own evaluation, i.e., the evaluation the Redskins Defense can be done using Pro Football Focus (PFF) - http://profootballfocus.com/cstats.php?tab=by_team&season=2009&teamid=32&stype=a&stats=d.

The offense can be evaluated in a similar approach.
Given Jason Campbell proven performance versus the quality of this years draft, QB is not a #1priority , but OL is at left tackle, right guard, and right tackle positions.  The directions the Skins go in free agency and their success in filling their needs will determine their draft picks from the 2nd round on.  Left tackle need will not be filled in free agency.

Some potential unrestricted free agents.
Guards:
1) Eugene Amano, 51st ranked guard -- overall rating slightly negative (-2.0), but is a good run blocker.  Pass protection and penaties reduced rating. http://profootballfocus.com/by_player.php?tab=by_player&season=2009&page=1&surn=A&playerid=1953

2) Rex Hadnot, 17th ranked guard at PFF – overall rating 6.5 (better performance than Amano) http://profootballfocus.com/by_player.php?tab=by_player&season=2009&page=0&surn=H&playerid=1892

Tackle: Levi Jones, LT, 2009 PFF overall rating was not good at left tackle.  He may do much better at right tackle. http://profootballfocus.com/by_player.php?tab=by_player&season=2009&page=3&surn=J&playerid=1018

Center: Casey Rabach – age factor is big considering the Teams’ intent for a youth movement.  This is already somewhat apparent at long snapper.

Linebackers:
Tully Banta-Cain, ROLB, Overall rating 21.8, run def. 11.1, pass rush 14.9, pass cov. -2.2, penalties -2.0.
http://profootballfocus.com/by_player.php?tab=by_player&season=2009&surn=B&playerid=1534&group=6

Paris Lenon,WLB/SLB, Overall rating 1.2, run def. 4.2, pass rush -1.0, pass cov. 0.0, penalties -2.0
http://profootballfocus.com/by_player.php?tab=by_player&season=2009&page=1&surn=L&playerid=751

Karlos Dansby    RILB, OVR 2.0, about as good on run defense and pass defense.
http://profootballfocus.com/by_player.php?tab=by_player&season=2008&page=&surn=D&playerid=1754

Safeties:
Ryan Clark, FS, PFF overall rating 1.2, pass coverage 3.2.  He is the only player over 30 that should be seriously considered in a youth movement.
http://profootballfocus.com/by_player.php?tab=by_player&season=2009&page=2&surn=C&playerid=1229

Bryan Scott, SS/WLB, Best at OLB, PFF overall rating 5.8, light weight for LB.
http://profootballfocus.com/by_player.php?tab=by_player&season=2009&page=1&surn=S&playerid=1370

Cornerback: Dunta Robinson, CB, not the greatest in pass coverage and run defense, but an improvement over some Skins cornerbacks in the 2009 season.  His performance was down rated due to penalties.  He is replacement quality only considering the stock of cornerback talent on the roster. http://profootballfocus.com/by_player.php?tab=by_player&season=2009&page=1&surn=R&playerid=1731

Retain Carlos Rogers.

Presuming linebacker, safety, and offensive guard needs are met in free agency, other needs would be filled by the draft or with UDFA rookies.  While additional draft picks maybe attained during the draft that assumption is not being made.  Others have made such assumption with good logic.  It may be possible to pick up additional moves by trading players on the Teams’ roster.  Flexibility in each round was allowed since the first choice may not be available.

1st round, 4th pick – offensive tackle – A) Anthony Davis B) Russell Okung.  Power run blocking could out weight pass protection considerations for this rookie slot.  Trent Williams had the before season lead, but Okung gained momentum in the rankings as the season progressed.  Momentum may now be changing since the junior left tackle potentials entered the draft.  Most mock drafts have not caught up with this phenomena yet.  The results combines and pro days will be large considerations.  In the 2009 draft Sebastian Vollmer was seen as a 4th round pick, he was selected in the 2nd round, and most significantly, out performed the 2009 1st round picks in PFF ratings.  
2nd round, 36th pick – offensive line, i.e., best available of Bryan Bulaga, OT;
Bruce Campbell, OT; Charles Brown, OT; (Currently the first three listed may not be available after the first round as well as Trent Williams, OT and Mike Iupati, OG.) Maurkice Pouncey, C; Vladimir Ducasse, OT; Jon Asamoah, OG; or Matt Tennant, C.  Centers can considered guard potentials. The youth movement may significantly alter the need perception at the center position.
4th round - Best QB or RB available in the round. Dan LeFevour may be gone by the 3rd round, but Ben Tate, RB, may still be around.
4th round alternatives
Lamarr Houston,    DT; Darryl Sharpton, ILB; Thaddeus Gibson, OLB, Roddrick Muckelroy, OLB; Chris Cook, CB; Kendrick Lewis, FS
5th Best running back available in the round: Joique Bell, RB; Charles Scott, RB
5th round alternatives
Jamar Chaney, ILB; O'Brien Schofield, OLB;  LeGarrett Blount, RB; Terrell Skinner, FS    ; Marshall Newhouse, OG
7th round     - Kevin Thomas, CB; Stephan Virgil, CB; Chris Hawkins, CB; Darius Marshall, RB; Chris Brown, RB.  (7 or FA - David Pender,CB; A.J. Jefferson, CB; Stafon Johnson, RB;