Jazz recommendations for a beginner?

if you like krall you may want to try sinatra "songs for swinging lovers". You may also want to try some of the songbook series from ella fitzgerald - maybe the cole porter songbook.

The term "Jazz" is an umbrella that covers a large variety of music. Traditional, Smooth, Vocal, and even New Age. Having said that I would like to recommend recordings by the following:

Cyrus Chestnut
Joshua Redmond
Eddie Harris
Grant Green
Lonnie Liston Smith
Dexter Gordon
Diane Schuur
Jimmy Scott
George Benson
Tom Scott
David Sanborn
Lou Donaldson
Gil Scott-Heron

Not really "Jazz" but worth a listen:

Acoustic Alchemy
The Rippingtons
Special EFX
Spyra Gyra

These artists are not hardcore "Traditional" but lean a little toward that way. Once you get familiar with jazz you can go deeper with Miles and Coltrane, who are kind of like drinking beer, at first you can't stand the taste, but over time as it grows on you, you love it.

Jazz is a very broad category (or genre) of music, along with others such as classical, country, blues, easy listening, folk, rap, latin, new age, pop, rock etc. Jazz has a number of subcategories (or sub-genres) as well, such as ballroom, big band swing, bop, dixieland/New Orleans, fusion, general, vocals, latin, smooth, traditional etc.

In exploring jazz one may discover they like one sub-genre but not another. Jorge, you are gravitating towards traditional vocals (Krall) but not towards general jazz (Davis). Identifying the sub-genre will help you find more of what you like.

At the same time, trying to categorize artists is sometimes a challenge. While Eva Cassidy on "Live at Blues Alley", is mostly "blues", most of her work is actually "folk".

Based on your attraction to Krall, I'd suggest artists like Karrin Allison, Shirley Horn, Jane Monheit, and Tierney Sutton. Then, experiment with other genres and see where it takes you.

A good number of people do not appreciate jazz when they begin this journey. But as they listen, they develop an ability to hear and relate emotionally to the music. There is broad agreement as to who the masters of this art form are. Books like The 101 Best Jazz Albums by Len Lyons are helpful. A beginner like yourself would probably benefit from a chronological approach. Four suggestions from traditional jazz would be:
Louis Armstrong and Earl Hines, 1928 (Smithsonian)
The Billy Holiday Story, Vol. II (Columbia, 1935-41)
Duke Ellington - 1940 (Smithsonian)
Solo Flight: The Genius of Charlie Christian
From modern jazz, you might consider any of the following:
The Very Best of Bird (The "Dial Sessions")
Bird/The Savoy Recordings (Master Takes)
Dizzy Gillespie: In the Beginning
Thelonious Monk: The Complete Genius
The Amazing Bud Powell, Vol. I
Clifford Brown: The Quintet
Sonny Rollins: Saxophone Colossus and More
Miles Davis/Gil Evans - Porgy and Bess
Wes Montgomery: While We're Young
John Coltrane: Giant Steps
The Best of John Coltrane: His Greatest Years
Bill Evans: The Village Vanguard Sessions
Oliver Nelson: The Blues and the Abstract Truth
I note that you are will be listening to CDs rather than LPs. Suffice it to say, there are many great recordings on LP -- like Clifford Brown With Strings -- that are difficult to recommend on CD. This is a subject for another thread, but thought I should give you a heads up on the problem of unlistenable CD transfers.