General Comments made by the treaty bodies are constructed with the purpose of clarification of how a given treaty provision is to be interpreted. They are a valuable source of guidance in this regard.
General Comment No.13 - The right to education
This general comment is especially useful as it provides an extremely detailed account of the right to education. For further explanation of the content of this general comment, follow the link to the excellent Litigating Economic, Social and Cultural Rights:
Legal Practitioners Dossier released by the Centre on Housing Rights and Evictions (COHRE), p.109
General Comment No.11 - Plans of action for primary education
General Comment No.9 - The domestic application of the Covenant
‘[W]hile the Covenant does not formally oblige States to incorporate its provisions in domestic law, such an approach is desirable. Direct incorporation avoids problems that might arise in the translation of treaty obligations into national law, and provides a basis for the direct
invocation of the Covenant rights by individuals in national courts. For these reasons, the Committee strongly encourages formal adoption or incorporation of the Covenant in national law.’ (Paragraph 8)
General Comment No. 3 - The nature of States parties obligations (art. 2, para. 1 of the Covenant)
The preamble to a treaty is useful in ascertaining the purpose of the law and therefore as a guide as to how it might be interpreted.
See the preamble here