Verbs in Irish are rather straightforward. There are only 11 irregular verbs, and their irregularity is largely confined to how they change between the tenses, rather than within the tenses themselves. Nevertheless, there can sometimes be doubts about various forms, so here are some resources that can be of assistance in this regard.
If you access An Foclóir Beag, which is the on-line Irish-Irish dictionary hosted by the University of Limerick:
and insert the imperative form of a verb (Note that Irish verbs are called by their imperative form, i.e. as in an order, e.g. Scríobh), a table will be presented containing all the forms of the verb. You can also call up the negative (diúltach) and interrogative (ceisteach) forms by clicking on the appropriate button.
WinGléacht can also be used for this purpose. Just insert the verb name (in the imperative again), and right click to see all forms of the verb. Some navigation may be required, as all information is not presented on the same page.
WinGléacht is a commercial application, i.e. it is not free. Further information is available elsewhere on this site, under the column Translation/WinGléacht.