iMovie is a brilliant tool for editing videos although it doesn't offer any DVD menu creation tools (although it does allow you to insert chapter markers as you edit).
iDVD is an option but it's not particularly intuitive or flexible. MovieGate however is an option worth considering as it allows you full control of DVD menu creation with no prior experience. MovieGate guides you through the full process from encoding video and audio to the creation of chapters, selection of compression rate and the combining of video and audio.
It allows you to select the sources of audio and video, the format, size, bitrate and set the quality of your edits. However, if you're not familiar with these concepts, it will also set them automatically for you although this doesn't always guarantee the best results. It could do with a preview function to see how it's going to look but apart from that, it's a good tool.
Intuitive and easy MovieGate is built so that you'll be able to create DVD menus and chapters without being an editing master.
