The CTEQ6.6 parton distribution functions (PDFs), derived from a global analysis of hard scattering data in the framework of general-mass perturbative QCD, are used to study theoretical predictions and their uncertainties for significant processes at the Fermilab Tevatron and CERN Large Hadron Collider (LHC). The study investigates the previously observed increase in predicted cross sections for W and Z boson production in the general-mass scheme compared to the zero-mass scheme. A novel method is introduced to constrain PDF uncertainties in LHC observables by exploiting correlations between PDF-induced effects and benchmark standard model cross sections. The study shows that the t̄t cross section can serve as a standard candle observable for LHC processes dominated by initial-state gluon scattering. Precise measurements of t̄t cross sections would reduce PDF uncertainties in predictions for single-top quark and Higgs boson production in the standard model and minimal supersymmetric standard model. The paper explores the implications of CTEQ6.6 PDFs for collider experiments, focusing on total cross sections at the Tevatron and LHC, W and Z boson production cross sections, top-quark production, and Higgs boson production. It discusses the correlations between PDFs and physical observables, emphasizing the importance of understanding how predicted cross sections change with improvements in the theoretical model and remaining freedom in PDF parameters. The study highlights the importance of using the most up-to-date PDFs to systematically explore the dependence of W, Z, and other "standard candle" cross sections on PDFs and QCD theory. It also examines the role of t̄t production as an additional standard candle process and identifies the main sources of PDF uncertainty in single-top production and Higgs boson production. The paper presents a detailed analysis of the correlations between PDFs and physical observables, including the impact of strangeness and charm on cross sections. It discusses the implications of these correlations for collider experiments, particularly the LHC, and the importance of precise measurements of cross sections for constraining PDF uncertainties. The study also explores the impact of intrinsic charm contributions on cross sections and the potential for using t̄t production as a standard candle observable. The paper concludes with a discussion of the implications of these findings for the calibration of the LHC luminosity and the precision tests of the Standard Model.The CTEQ6.6 parton distribution functions (PDFs), derived from a global analysis of hard scattering data in the framework of general-mass perturbative QCD, are used to study theoretical predictions and their uncertainties for significant processes at the Fermilab Tevatron and CERN Large Hadron Collider (LHC). The study investigates the previously observed increase in predicted cross sections for W and Z boson production in the general-mass scheme compared to the zero-mass scheme. A novel method is introduced to constrain PDF uncertainties in LHC observables by exploiting correlations between PDF-induced effects and benchmark standard model cross sections. The study shows that the t̄t cross section can serve as a standard candle observable for LHC processes dominated by initial-state gluon scattering. Precise measurements of t̄t cross sections would reduce PDF uncertainties in predictions for single-top quark and Higgs boson production in the standard model and minimal supersymmetric standard model. The paper explores the implications of CTEQ6.6 PDFs for collider experiments, focusing on total cross sections at the Tevatron and LHC, W and Z boson production cross sections, top-quark production, and Higgs boson production. It discusses the correlations between PDFs and physical observables, emphasizing the importance of understanding how predicted cross sections change with improvements in the theoretical model and remaining freedom in PDF parameters. The study highlights the importance of using the most up-to-date PDFs to systematically explore the dependence of W, Z, and other "standard candle" cross sections on PDFs and QCD theory. It also examines the role of t̄t production as an additional standard candle process and identifies the main sources of PDF uncertainty in single-top production and Higgs boson production. The paper presents a detailed analysis of the correlations between PDFs and physical observables, including the impact of strangeness and charm on cross sections. It discusses the implications of these correlations for collider experiments, particularly the LHC, and the importance of precise measurements of cross sections for constraining PDF uncertainties. The study also explores the impact of intrinsic charm contributions on cross sections and the potential for using t̄t production as a standard candle observable. The paper concludes with a discussion of the implications of these findings for the calibration of the LHC luminosity and the precision tests of the Standard Model.