The custom of the Sephardim, and some groups among Ashkenazim, is to recite the "Hodu" paragraph each morning before Baruch She'amar, while other Ashkenazim recite this prayer after Baruch She'amar. This paragraph was composed by King David, and it was recited in the Temple each morning during the offering of the daily Tamid sacrifice.
Unfortunately, many people are lax with regard to the recitation of this prayer and skip straight to Baruch She'amar. This is not proper; Hodu is an important part of the morning service, and one should not treat it lightly. This is particularly so according to the view of Kabbalists, who see Hodu as beginning a new stage of the prayer service, such that one who skips to Baruch She'amar cuts into the middle of this section.
Rabbi Meir Shapiro of Lublin (Poland, 1887-1933) made an insightful comment concerning the divergent practices with regard to the recitation of Hodu. As mentioned, the Sephardim recite Hodu before Baruch She'amar, whereas many Ashkenazim recite Hodu only after Baruch She'amar. All Jews, however, meet up again at the paragraph "Yehi Chevod Hashem L'olam" ("May Hashem's glory last forever"). What this demonstrates, Rabbi Shapiro remarked, is that although different groups of Jews follow different customs and practices, ultimately they all work together towards realizing the common goal of "Yehi Chevod Hashem Le'olam" – bringing honor to God. Everyone must therefore remain loyal to his community's Minhagim (religious customs), as they are all geared towards the joint, overarching goal of showing honor to the Almighty.
Summary: The Hodu prayer, which is recited either before or after Baruch She'amar, depending on one's custom, constitutes an important part of the prayer service and therefore should not be skipped.