seed questions?

How long does it usually take for the average
seed to sprout roots when germinating?
and do they get bigger before they sprout roots?
I'm new to growing with seeds I've been growing by clones so far

Probably as many ways to germ seeds as there is strains. In my paper towel method i will have a tap root in 2 days, some soil methods take a week or more. They don't get bigger, they split at the seam, stick out a little tongue which is the tap root, which gets longer until a little root with 2 leafs sheds the shell. In soil, you just see the shell come out then expose the 2 water leafs.

Well in my experience my seeds usually germinate in 24-48 hrs and sprout a seedling in 1-3 days.

i plant directly into soil normally if there going to pop the poke out of the soil within 2-10 days sometimes up to 14 i find after 14 days your chances for gemination are slim to none
roots grow as the plant grows