NGC 4790 in Virgo has a 12th mag supernova called 2012au that was discovered on the 14th. That means this sucker is going to get bright and should be easy to view. It is a Type Ib which will mean it will brighten quick, and then fade quicker than a Type II would.
Here is the info:
2012au (= PSN J12545218-1014502) (= SNhunt117), CBET 3052 discovered 2012/03/14.450 by Catalina Real-Time Transient Survey and Stan Howerton
Found in NGC 4790 at R.A. = 12h54m52s.18, Decl. = -10°14'50".2
Located 3".5 east and 2".0 north of the center of NGC 4790 (Discovery image)
Mag 12.7:3/16, Type Ib (References: CBAT TOCP, ATEL 3967, ATEL 3968, ATEL 3971)
2012au images sub-page
Just in time for a Messier Marathon, Messier 95 as a bright SN that was discovered on 17th of March in an outer arm of Messier 95. Already in the 12th mag range this one will brighten also and is really close to Mars right now. Here is a link to info on this one. This one is so new they haven't been able to identify what type it is. I'm going for both this week!
Here is the info on the SN in Messier 95:
PSN J10435372+1140177, CBAT TOCP discovered 2012/03/16.8493 by J. Skvarc; Alessandro Dimai (Italian Supernovae Search Project)
Found in M95 at R.A. = 10h43m53s.72, Decl. = +11°40'17".7 (= NGC 3351)
Located 60" west and 115" south of the center of M95 (Skvarc discovery image) (Dimai discovery image) (Nick James image) (David Strange image) (Stan Howerton image) (William Wiethoff image) (Martin Mobberley image) (Maurice Gavin image) (Stephen M. Brincat image) (Fabio Martinelli image)
Mag 13.1:3/19, Type unknown (References: ATEL 3979)
Astrobob blog, Beautiful Start blog, blog, Astronomy blog, Astronet in Swedish [translate]
Here is the link to Bright Supernova on the info for this one.
Now if your interested in some Messier Marathon Charts and links I want to provide some to you in case you find them helpful. I will openly admit I've only done one, and that was enough for me. I prefer to work my current observing projects.
Rob Hawley has a nice set of charts (dated to 2006) on doing a Messier Marathon with finder charts. Here is the link to his site.
AstroTulsa over on Yahoo Groups has a post by Tamara that has a 2012 edition of finder charts for a marathon. Here is the link for that.
Ten Minute Astronomy Blog has a nice feature on a Messier Marathon with tips, charts and logs.
From Bel Tor Observatory is a post with a link to some more finder charts. Nice charts here for the Messier.
That's not a a lot, but they are the free one's I found and that I thought were decent. If your engaging in a Messier Marathon, good luck, arrive early and set up before the sun goes down so you can get started. Plan out your night a head of time as that helps also. Good luck!